Lambda sensor Q MOT failyer :0(
05-17-10, 11:04 AM
#16
This is a little difficult to understand, but it appears you have failed the UK emissions test, and you have a CAI, cold air intake. You had 4" mufflers, that were fitted with something to change the exhaust pressure. It is a bit difficult, even though we are all speaking English, there is a bit of language difference.
- O2 sensors, when they fail they usually create a check engine light situation because of the circuit open or fuel trim not within range, usually brings on a CEL. You are correct, there are 4 per car as it is a dual exhaust V8. If there truly is no CEL, then the O2 sensors are likely functioning fine. It is likely the other stuff that you added to the mixture which caused it to fail.
- The cold air intake can fool your ecu if it is not the correct diameter of the original intake. lets say stock is 50mm, and you have 75mm, with the exact same sensor, you will be running lean just because of the amount of air increase. (Now this is in theory, because the ecu will adjust the fuel trim according to the O2(Lambda) sensors.
- Dual 4" exhaust was never meant to be put on a stock 1UZ, even with whatever it is you've added. Do you have the stock, OE exhaust on there now with the stock mufflers, catalytic converters on as well?
p.s. Adding back pressure will not mess up the readings they either work or they don't. Too little is not a problem, too much and your car won't run , all it will do is alter the speed of the flow. Primary O2 sensor is the one pre-cat, the secondary is post-cat.
- O2 sensors, when they fail they usually create a check engine light situation because of the circuit open or fuel trim not within range, usually brings on a CEL. You are correct, there are 4 per car as it is a dual exhaust V8. If there truly is no CEL, then the O2 sensors are likely functioning fine. It is likely the other stuff that you added to the mixture which caused it to fail.
- The cold air intake can fool your ecu if it is not the correct diameter of the original intake. lets say stock is 50mm, and you have 75mm, with the exact same sensor, you will be running lean just because of the amount of air increase. (Now this is in theory, because the ecu will adjust the fuel trim according to the O2(Lambda) sensors.
- Dual 4" exhaust was never meant to be put on a stock 1UZ, even with whatever it is you've added. Do you have the stock, OE exhaust on there now with the stock mufflers, catalytic converters on as well?
p.s. Adding back pressure will not mess up the readings they either work or they don't. Too little is not a problem, too much and your car won't run , all it will do is alter the speed of the flow. Primary O2 sensor is the one pre-cat, the secondary is post-cat.
05-18-10, 07:34 AM
#18
CEL means... Check Engine Light = CEL...
Your stock exhaust is like <2", I think 1.75", however JBrady is the real exhaust wizard and would know way more than I would in this department. 4" back is for heavy heavy heavy breathing cars including turbo or supercharged. A single 3" might be too big for a stock 1UZ. Try going back to the stock, OEM, exhaust that was originally on your car, you will likely see better results and shouldn't fail your inspection.
Your stock exhaust is like <2", I think 1.75", however JBrady is the real exhaust wizard and would know way more than I would in this department. 4" back is for heavy heavy heavy breathing cars including turbo or supercharged. A single 3" might be too big for a stock 1UZ. Try going back to the stock, OEM, exhaust that was originally on your car, you will likely see better results and shouldn't fail your inspection.
05-19-10, 07:23 AM
#22
Yeee you got it bang on och co2 fine other gas reading fine it says on failier paper exhaust emisions lambder reading after 2nd fast idle outside spec limits but test guy sagas reading all good lambder sensor not good so your guess is as good as mine O car is a 96 4.0 quad cam (pos denso cams fitted) 32 vaulve
05-19-10, 10:26 AM
#23
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3 parts to the emission test here 2 parts past ok but the said that the lambda sensor it self was giving a strange reading and above the required level
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