Oxygen sensor

[kkapoor]

Hi guys, Can anyone be so kind to give me some information on oxygen sensors. i dont know what they are for but i would certainly like to know when I should be getting them changed. I own an A4 11 Whats the average km that an oxygen sensor works for? Thanks everyone.

[Saleem]

Hi Kakapoor

as you mentioned your car is A4 2011 which mostly 1.8T or 2.0T

Oxygen sensors are fitted in the exhaust system to evaluate CO usually it remains for 8 or 10 years as per service divisors told me few years ago but if you have a DTC reporting Oxygen sensor it would tell you which type of trouble you have Ex.circuit short/grounded/impossible signal/ low or high resistance or it would notify you mixture too reach / lean

so for circuit issues you may double check on wiring and connectors if all fine you may double check your spark plug

for other issues you need to check spark plugs if it's ok go forward to for secondary air pump (compressor) or secondary air vent which is a small electrical motor with air turbine pumping air from intake filter to exhaust to lower CO ratio (emission control) and check EGR valve which is related to secondary air pump.

for turbo engines like yours you may check vacuum lines leakages for waste gate operation on the turbo if you have a black smoke.

Good Luck!