QUOTE (supunna_picta @ Aug 19 2007, 03:22 AM). The product is excellent. with unbelievable performance for the money. 2012 AUDI A6 (C7) 2.0L CAEB - PRE / POST CAT O2 OXYGEN LAMBDA PROBE SENSOR SET-2 . This is a TSB regarding the P2096 problem. In most cases, a vehicle with an inefficient catalytic converter will continue to run just fine. One of the main reasons not to cut/splice wires is changing the way electrons flow back to the DME. Even though both O2 sensors are four wire, heated O2 sensors, there are definitely differences that the Motronic can detect. 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. Use live data to check for signal if the sensor wiring is difficult to access. Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. If both O2 sensors and catalyst was replaced then you may have an exhaust leak at the manifold or pipes. Whereas wide-band is 1V -5V, allowing for more detail when not at ideal operating conditions. Do Not Sell or Share My Personal Information. In an effort to diagnose the faulty component I have been monitoring the pre and post cat O2 sensors using the graph displays on the Torque OBD2 app, but I need some help understanding the readings. I know there wasnt a difference on my 02 SS. Form: Not sure if the sensor itself is any different but I know the connectors are (at least on the 04's) 2004 Yellow M6, 1 of 1014 Is upstream pre or post cat? 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. Common sources of contamination include an excessively rich fuel mixture condition or oil blow-by in an older engine and engine coolant being burnt in the combustion chamber as a result of an engine gasket leak. When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. The most commonly used sensor has a Zirconia element, producing a voltage when there is a difference in oxygen content between the two electrodes. I have two new original postcat sensors. Our P2096 fault code problem has now been resolved. 0 Being lean, 0.5 being ideal and 1.0V being rich. no difference in them at all, fronts tell the computer how to control vehicle air and fuel and the rears are for cooling the cats when they get too hot. Finally, run the ignition and confirm that the check engine light is extinguished, then perform a road test. Check the O2 sensor is reading correctly by confirming the O2 value with a four, or five gas emission analyser. 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. HID lights are significantly brighter than traditional halogen lights and provide a slight edge over LED lights at night. Since the oxygen sensor is in the exhaust stream, it can become contaminated. OEM numbers are obviously different. Content on spyderchat.com is generated by its users. The downstream oxygen sensor detects the change and informs the vehicles computer. Fantastic products and support with unbelievable performance for the money. These can all affect the oxygen sensors response characteristics, resulting in an extended response time or a shift in the sensor voltage curve and in the long run reduced sensor performance. 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. A sensing element sits inside the sensor, encased in a steel housing. Free shipping . Click to enlarge. These cookies will be stored in your browser only with your consent. Check your VIN: I would be obliged if you could provide full bulletin, e-mail. All three O2 sensors are intechangeable. 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. How do you fix P0420 catalyst system efficiency Below Threshold Bank 1? . Not having ordered on the internet before i didnt struggle at all. The ECU wont be able to adjust fuel trims properly. A typical Zirconia lambda sensor has four wires. Once unscrewed, discard the old sensor and replace with the new unit. Closing out this thread for the troubleshooting masses. Tally how many spark plug wires are present. 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. Read any fault codes using a diagnostic tool. ,t.c.bypass,descreened m.a.f. Come join the discussion about M performance, turbo kits, engine swaps, builds, modifications, classifieds, troubleshooting, maintenance, and more! What's wrong with this picture? The "pre-cat sensor" regulates fuel supply, while the downstream sensor measures the efficiency of the catalytic converter. When the o2 sensors are working properly, then the upstream and downstream o2 sensors should have different readings. But opting out of some of these cookies may affect your browsing experience. It lets you see what you previously had to guess was happening. The Club assumes no responsibility for any effects arising from errors or omissions. Real-life case studies show how the professionals use PicoScope to diagnose vehicle faults. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. 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. You never never never get anything done at the dealer, NEVERRRRRR. Local autozone had it in stock less than $100. are the pre cat and post cat 02 sensors the same? You also have the option to opt-out of these cookies. check out the. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. Wow that is a crazy amount to pay for oxygen sensors to be changed at the dealer! On an oscilloscope, the resultant waveform should look as the illustration above. Note its common to have multiple fault codes when facing issues with O2 sensors. Members are advised to consult qualified specialists for information, advice and assistance on matters connected with their cars at all times. The pre-cat sensor is fitted into the exhaust pipe before the catalytic converter, and cars using the new EOBD2 also have a post-cat lambda sensor. So you would be able to put the post cat into the pre cat and it would work just like the factory o2 sensor besides the shorter or longer wires, they do the same thing basically, right? I tried a couple of them and got codes before I even started the car. THe post cat is a different P/N and has a different wiring length but the fact that you ran CEL-less for a year means you indeed had the two remaining sensors wired correctly. Come discuss mods, horsepower, engine specs and more! 325 e, i have 03 bmw 330xi and bank 2 oxigen sensor wire got burn out touching the four wire, i split it them but now get code p0031,p0600,p0051,p0037 and p0057 can anyone tell me how to check the voltage on those wire or the wiring schematic. The cookies is used to store the user consent for the cookies in the category "Necessary". Downstream Sensor is in the Exhaust Pipe Post-Cat. 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. Is the upstream and downstream O2 sensor the same? 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. 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?). AU $309.99 + AU $45.00 postage . Lambda sensors have an internal heater, so check the resistance of the heater it will usually be quite low.