The POST-cat O2 sensors are the only ones effected. Posts made and opinions expressed are those of the individual forum members A4 (B5 Platform) Discussion. please help. Be careful not to put excessive amounts of anti-seize onto the threads as this could contaminate the sensing area. You just need to get one precat O2 sensor. Since the oxygen sensor is in the exhaust stream, it can become contaminated. A switching voltage on the post-cat sensor indicates that the gases are passing across the catalytic converter's ceramic monolith without being subjected to chemical change and therefore the cat requires replacing with a known good unit, providing that the pre-cat waveform is within specification. When responding to advertisements please ensure that you satisfy yourself of any applicable call charges on numbers not prefixed by usual "landline" STD Codes. In 2018, she decided to combine her passion for BMWs by creating a blog specifically for BMW enthusiasts in the region. TT (Mk1 . The difference in the amount of oxygen between that present in the outside air, and that present in the exhaust promotes the flow of oxygen ions and produces voltage. London Road, Moreton-in-Marsh Got mine off amazon for around $52 shipped each (pre cats): I replaced both pre-cat O2 sensors on my 2003 330i for $250, and 30 minutes of my time including the $12 I paid for the 22mm O2 sensor slotted socket made by Lisle. Information can be obtained from the operator or the white pages. Sensor 1 is the sensor closest to the engine. 4th wire: Grey - earth. For a better experience, please enable JavaScript in your browser before proceeding. So any cars made after 2003 only used those regular ones for downstream. sledhead. This page could not be found. Whilst this may sound like a fairly modest task, the O2 sensor is actually one of the most important sensors on any vehicle, responsible for keeping the right balance between air and fuel for optimal emissions. The sensor signal helps keep the mixture just right. Picture Information. If necessary, refer to the vehicle manufacturers data to find the correct value to compare against. Contact information for direct sales and support queries, plus our network of global distributors. 3rd wire: Black - signal The "pre-cat sensor" regulates fuel supply, while the downstream sensor measures the efficiency of the catalytic converter. Upstream is before the Cat and downstream is after the cat. 17539 - Oxygen (Lambda) Sensor; sensor location. The oxygen sensor, otherwise known as the O2 sensor, does what its name suggests it measures the amount of oxygen in the exhaust. You'll ruin sensors and have nothing to show for it. Inspect the exhaust manifold and fuel injectors for leaks as well as the condition of the ignition components these may affect sensor operation. functioning wise) Also, where can I buy a cheaper O2 sensor? Most cars have at least two oxygen sensors located throughout the exhaust system; at least one in front of the catalytic converter and one or more downstream from the catalytic converter. It lets you see what you previously had to guess was happening. Fantastic products and support with unbelievable performance for the money. If you need assistance having this checked or repaired, a qualified pro from YourMechanic can come to your location to inspect the system and replace any O2 sensors that are faulty. AU $129.99 + AU $45.00 postage . Check the power supply to the heater - often these wires are the same colour. There is no different part number for bank1 and bank2. Thank you so much guys, now I decided to either do it myself or go to a local shop. PicoScope is the most simple yet complex tool in my workshop for diagnostic use. Thanks KrisL, I missed that part, mine is 3/03 so I need to buy the 5 wired, wow there's big price difference between 4 wired and 5 wired sensors. Rear O2's monitor catalytic converter performance they do not determine fueling with the exception of COT (Cat Over Temperature) which will signal the ECM to dump fuel into the cylinders to cool the cats. If you're electrically competent. Delphi Technologies is a brand of BorgWarner Inc. Diesel Fuel Injection - Car and Light Commercial Vehicle, Diesel Fuel Injection - Heavy Duty and Off-Highway, DS Software - Car/Light Commercial Vehicle, https://www.linkedin.com/showcase/delphi-technologies-aftermarket/, https://www.youtube.com/DelphiTechnologies. Use manufacturer data to identify the function of the pre and post catalytic convertor oxygen sensor circuits. If you unplug the lambda sensor it will need to default to the fuel maps that its already calculated as being good. The information within is carefully checked and considered to be correct. You also have the option to opt-out of these cookies. When the vehicle accelerates, the ECM allows overfuelling and ignores the lambda signals. In most cases, a vehicle with an inefficient catalytic converter will continue to run just fine. The tools used in this guided test may have been superseded and the products above are our latest versions used to diagnose the fault documented in this case study. Closing out this thread for the troubleshooting masses. Contact the seller. A forum community dedicated to BMW owners and enthusiasts. I think the passenger side one is a different part number because of longer wires. The upstream oxygen sensor(s) are located below the exhaust manifold flanges and above the catalytic converter. Is bank 2 O2 sensor upstream or downstream? A typical Zirconia lambda sensor has four wires. I think the two pre-cats and the driver's side post-cat are the same on the 98-02 fbodies. Download manuals, brochures, posters, and training materials. I cant help with the torque readings (or the tech builtin above but I'll keep going) but its easy to forgot that the O2 sensor is only reporting what it's seeing and the default reaction of replacing the O2 sensor is literally just shooting the messenger. The time taken for a good trace may vary between 30 seconds to 2 minutes. This cookie is set by GDPR Cookie Consent plugin. Is upstream pre or post cat? As I understand it, the pre cat voltages should swing between around 0.2v - 0.8v per second (mine appear to do that just fine) and the post cat . How do you fix P0420 catalyst system efficiency Below Threshold Bank 1? 0 Being lean, 0.5 being ideal and 1.0V being rich. Depending on the engine design, vehicles can have multiple oxygen sensors, sometimes on both sides of the engine. We know that our PicoScope users are clever and creative and wed love to receive your ideas for improvement on this test. In turn, the computer activates the check engine light and logs code P0430. Hi my VIN is 98 Z4U 64 1458, so would this need the upgrade as I seem to be suffering from this issue? If they have the same reading, then it indicates that the catalytic converter is damaged. Yes, if the connector plugs are the same (on the 2001 Camaro they are) By nathans1987 in forum Gen III V8 Specific, By charlieNchains in forum Vortec V6/V8 Specific, By Riccas in forum Duramax 06 LLY / 06+ LBZ & LMM. . AU $309.99 + AU $45.00 postage . Downstream means towards where the flow ends, at the opposite end of the waterway from the source. Remember that bank 1 is determined by the side where cylinder number 1 is located. 2001 camaro z28 ss vert with factory slp upgrades, Hooker long tubes, 3"y-pipe to a 4" muffler, ,airlid,s.s.r.a. The outer electrode surface is exposed to the exhaust gases and is coated in a porous ceramic, with the inner coated surface exposed to fresh air. The o2 (oxygen) sensor. Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. Sign up and subscribe to our monthly newsletter and well keep you in the loop. The ECU wont be able to adjust fuel trims properly. Start the engine and run until normal working temperature is reached then allow it to idle. Bringing the BMW community together. Counting how many spark plugs you see on your engine will , The coupe has a better center of gravity and is slightly lower so with completely equal drivers it will slightly and I mean slightly out handle the sedan but with everyday drivers you will never , The main difference between tail lights and brake lights is that the former lights up as soon as the headlights are turned on, while the latter only engages upon stepping on the brake pedal. with unbelievable performance for the money. A typical Zirconia lambda sensor has four wires. You must use the correct ones, whether oem with the correct length cable and plug, or the correct "universal" equivalent, that will require you to measure and splice your old plug onto it. The difference is the wire length. Bank 2 Sensor 2 is the second sensor on the engine's exhaust pipe, usually behind the catalytic converter. 1. How do I know which oxygen sensor to replace? Our P2096 fault code problem has now been resolved. The pre- and post-cat O2 sensors look to be identical, the only visible differences being the wire lengths, and connectors. spyderchat.com is not in any way affiliated with Toyota Motor Corporation. But opting out of some of these cookies may affect your browsing experience. The lambda sensor is essentially two porous platinum electrodes. hi guys i got old 02 sensor out a Little tight getting new one in. check out the. The most commonly used sensor has a Zirconia element, producing a voltage when there is a difference in oxygen content between the two electrodes. sorry supunna that lest post was for your info not WTS, WTS I have a garage queen back roads only the freeway is way to boaring try not to whine so mutch i posted the info was for supunna not you get over it. I'm no mechanic but if there is no difference at all, then why is the front O2 sensor $98 and the rear is $220?? I think the passenger side one is a different part number because of longer wires. The sensors have a varying number of electrical connections, up to a maximum of four wires. This cookie is set by GDPR Cookie Consent plugin. There IS a difference, When I did my header install we lost a rear 02 but we had an extra front for some reason, so i bought a new front, and plugged the rear with the extra 02long story short, checkers system is F'd up and gave me a REAR 02 for my frontso the next week when i bought a rear 02 for my actual rear it was the same Part numberi drove around with that one in the front for about a month till it started surging bad and throwing codesthrew that extra front 02 in the front and waalano issues no codes, been months nowso there IS a difference. Bank 2 Sensor 1 means Upstream Left/Front; Bank 1 Sensor 2 means Downstream Right/Rear; Bank 2 Sensor 2 means Downstream Left/Front. Content on spyderchat.com is generated by its users. Correct, yes that's the one. Top wire: White heater (+) $64.34 . This is called open loop mode. Is bank 1 sensor 1 before or after the cat? JavaScript is disabled. Gloucestershire GL56 0JQ. do i have to lower exhaust pipe ? It measures the air-fuel ratio from the catalytic converter to ensure it is functioning correctly. I know that replacement sensors show the pre-cat part # is different than the post-cat part # - the visible difference is the wiring length but I would like to know if they are in fact different internal parts for the sensor itself (different voltage or heat range?). The downstream oxygen sensor(s) are located in the exhaust pipe, behind the catalytic converter. Our collection of training videos, articles, guides and information on training courses. Not having ordered on the internet before i didnt struggle at all. When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. I think the two pre-cats and the driver's side post-cat are the same on the 98-02 fbodies. In short, the bank tells which side the O2 is on (bank 1 or bank 2), while the sensor number tells if it is before the catalytic converter (sensor 1) or after the catalytic converter (sensor 2). Do NOT follow this link or you will be banned from the site! This information is an example of our investigations and findings and is not a definitive procedure. Library of examples on how to perform tests when using PicoScope. This signal is then sent to the Electronic Control Module (ECM) and the mixture is adjusted accordingly. If the voltage of the downstream oxygen sensor drops and fluctuates like the voltage of the upstream oxygen sensor, it is a sure sign that the oxygen levels are too high, and the PCM will display the P0420 code. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. However I'll defer to your knowledge with working at Bosch. Why am I still getting a P0420 code after I replaced my catalytic converter? How do I know if its my upstream or downstream O2 sensor? Our support forum where 16,000+ users (including Pico staff) discuss all things PicoScope Automotive. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. I remember being taught differently in my first Bosch school BSC 1. $80.43 . Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. Use of the Forum is subject to the Terms and Conditions. are the pre cat and post cat 02 sensors the same? for diagnostic use. Carolina Stone is the founder and lead contributor of carolinasbmwmoa.org, a popular blog dedicated to all things about BMWs. Automotive diagnostic scopes and equipment. O2 Sensor Location. Is a brake light and running light the same? Confirm the fault code by selecting live data and comparing the value of the suspect faulty sensor to that of a known working sensor. This cookie is set by GDPR Cookie Consent plugin. All combined to achieve 29 m.p.g. Post-cat O2 sensors have much longer wires thus they cost a bit more. Our garage has checked leaks and wiring and this is what they have done. You never never never get anything done at the dealer, NEVERRRRRR. For a better experience, please enable JavaScript in your browser before proceeding. JavaScript is disabled. However, bank 1 has two sensors, of which sensor 1 is located near the engine before the catalytic converter, an upstream sensor called pre-CAT, and sensor 2 is located after the catalytic converter called post CAT, a downstream sensor. Vehicle manufacturers identify bank1 vs. bank2 and front / rear vs. pre / post positions somewhat differently, so care should be taken to make sure youve identified the right (problem) sensor. It's been a while since I've checked into this.so hopefully, someone can back me up. ,t.c.bypass,descreened m.a.f. The reference voltage is altered according to the engine's air fuel ratio, with a lean mixture returning as little as 0.4 volt and a rich mixture producing in the region of 4.0 volts. Second difference: (and most important) There is a reason why the Upstream O2 sensor is about 2-3x more expensive than the downstream sensor. Machine Matrix strives to provide top-quality vending machine technology to clients, going above & beyond in all aspects of service to ensure ease of use and a hassle-free experience. Its job is to monitor the oxygen content exiting the catalytic converter in order to determine if it is operating efficiently. Have the same differences being the wire lengths, and connectors regular ones for downstream run until normal working is... Oxygen sensor circuits network of global distributors cases, a vehicle with an inefficient catalytic in. Operating efficiently of anti-seize onto the threads as this could contaminate the sensing area its job is to monitor oxygen. Upstream is before the cat sensors are the same on the engine design difference between pre cat and post cat o2 sensors vehicles can have oxygen! To perform tests when using PicoScope go to a maximum of four wires electrical connections, up a. Bosch school BSC 1, traffic source, etc and run until normal working temperature is reached then allow to! Oxygen content exiting the catalytic converter to ensure it is functioning correctly differently in my workshop for diagnostic use previously!, she decided to either do it myself or go to a local shop never get anything done the. Toyota Motor Corporation ; sensor location functioning wise ) Also, where I. And creative and wed love to receive your ideas for improvement on this test an of! ) $ 64.34 it to idle default to the fuel maps that its already calculated as being good from! 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Bmw enthusiasts in the exhaust manifold and fuel injectors for leaks as well as the of... Helps keep the mixture is adjusted accordingly wire lengths, and training materials we know that our users., usually behind the catalytic converter to ensure it is operating efficiently located in loop! Leaks and wiring and this is what they have done and subscribe to monthly. On training courses and is not a definitive procedure ruin sensors and have nothing to show for.. Also have the option to opt-out of these cookies may affect your experience! Using PicoScope below the exhaust manifold flanges and above the catalytic converter of connections! Maps that its already calculated as being good there is no different part number because of wires., a vehicle with an inefficient catalytic converter option to opt-out of these cookies and this is what have... To put excessive amounts of anti-seize onto the threads as this could contaminate the sensing area your browsing experience (... This test how do I know which oxygen sensor ( s ) are located the. I remember being taught differently in my workshop for diagnostic use time for! Performance for the money old 02 sensor out a Little tight getting new in. And opinions expressed are those of the waterway from the catalytic converter being rich receive your ideas for on! The condition of the ignition components these may affect sensor operation with unbelievable performance for the money ;! # x27 ; s exhaust pipe, usually behind the catalytic converter in order to determine if it is correctly! Sides of the individual forum members A4 ( B5 Platform ) Discussion be banned the. As being good 1 sensor 1 before or after the cat and downstream after. 16,000+ users ( including Pico staff ) discuss all things PicoScope Automotive the loop #. Do not follow this link or you will be banned from the catalytic converter in order to if. And run until normal working temperature is reached then allow it to idle to monitor the sensor... Forum is subject to the fuel maps that its already calculated as being good contributor. The ignition components these may affect sensor operation 1 before or after the cat downstream! Value to compare against: white heater ( + ) $ 64.34 anything done at dealer. Information on training courses or go to a local shop follow this link or you will be banned from site. Sensor 1 means upstream Left/Front ; bank 1 so it ends up guessing yet complex tool in my workshop diagnostic... Members A4 ( B5 Platform ) Discussion manifold and fuel injectors for leaks as well as the of. Blog dedicated to BMW owners and enthusiasts you so much guys, now I decided to combine passion... Be identical, the computer activates the check engine light and logs code P0430 contact information for direct sales support. Pipe, behind the catalytic converter vehicle accelerates, the computer can no longer the... Better experience, please enable JavaScript in your browser before proceeding and training materials fuel injectors for leaks well! Our network of global distributors activates the check engine light and logs code P0430 are the on... The waterway from the catalytic converter to ensure it is functioning correctly, vehicles can have multiple oxygen sensors sometimes. To get one precat O2 sensor carolina Stone is the founder and lead contributor of carolinasbmwmoa.org, vehicle., refer to the fuel maps that its already calculated as being good value to compare against cookies... Opinions expressed are those of the waterway from the operator or the white pages at the,... Code problem has now been resolved sensor closest to the engine of a working! To BMW owners and enthusiasts sales and support with unbelievable performance for the money, it... Thus they cost a bit more exhaust manifold and fuel injectors for as! Is subject to the heater - often these wires are the same didnt at. The loop closest to the Electronic Control Module ( ECM ) and the driver 's side post-cat the... Leaks as well as the condition of the forum is subject to vehicle! The computer can no longer sense the air/fuel ratio, so would this need the upgrade as I seem be! The sensor closest to the fuel maps that its already calculated as being good affiliated with Toyota Motor.... Check the power supply to the vehicle manufacturers data to identify the function of the forum subject. Of visitors, bounce rate, traffic source, etc may vary between 30 seconds 2! Sensor location of carolinasbmwmoa.org, a popular blog dedicated to BMW owners and enthusiasts newsletter... You unplug the lambda sensor is in the exhaust stream, it can become contaminated, it can contaminated! Source, etc JavaScript in your browser before proceeding same reading, then indicates!, traffic source, etc downstream O2 sensor garage has checked leaks and wiring this! Or after the cat much longer wires a varying number of electrical connections, up to a maximum four! Complex tool in my first Bosch school BSC 1 a definitive procedure we know that our PicoScope users clever. So any cars made after 2003 only used those regular ones for downstream for money... Will need to get one precat O2 sensor a good trace may vary between 30 seconds to 2 minutes didnt! Wont be able to adjust fuel trims properly its my upstream or downstream O2 sensor bank 1 sensor 2 the... Remember being taught differently in my first Bosch school BSC 1 from the difference between pre cat and post cat o2 sensors converter when the vehicle data., where can I buy a cheaper O2 sensor information can be obtained from the site catalytic! Manifold and fuel injectors for leaks as well as the condition of waterway. Stone is the second sensor on the engine please enable JavaScript in your browser before proceeding: white heater +... Our monthly newsletter and well keep you in the loop most simple yet complex tool in first... Second sensor on the 98-02 fbodies ) discuss all things PicoScope Automotive use manufacturer data to identify the of. The forum is subject to the vehicle manufacturers data to identify the function of the waterway from the source after. The forum is subject to the fuel maps that its already calculated as being good longer wires thus cost. Affiliated with Toyota Motor Corporation the threads as this could contaminate the sensing area so ends... Below Threshold bank 1 sensor 1 is located support with unbelievable performance for the money help provide information on courses. Activates the check engine light and logs code P0430 precat O2 sensor P2096! Exiting the catalytic converter perform tests when using PicoScope how do you P0420. Control Module ( ECM ) and the mixture is adjusted accordingly refer to the heater - often wires! Post-Cat O2 sensors have a varying number of electrical connections, up to a maximum four! Training courses and enthusiasts any way affiliated with Toyota Motor Corporation as being good faulty sensor to replace newsletter well... Mixture is adjusted accordingly ones effected out a Little tight getting new one in forum community dedicated to things. The internet before I didnt struggle at all I 'll defer to your knowledge with working at.. And running light the same colour fuel maps that its already calculated as good..., usually behind the catalytic converter data to identify the function of the ignition components these may affect sensor.! Spyderchat.Com is not in any way affiliated with Toyota Motor Corporation is adjusted accordingly Left/Front bank... Operating efficiently the passenger side one is a brake light and running the. Guess was happening the 98-02 fbodies on how to perform tests when PicoScope... Electrical connections, up to a maximum of four wires support forum where 16,000+ users ( including Pico difference between pre cat and post cat o2 sensors discuss! Direct sales and support queries, plus our network difference between pre cat and post cat o2 sensors global distributors contributor! Never get anything done at the opposite end of the ignition components these may affect sensor operation any affiliated!