I got this car recently and the check engine light came on, the codes reported that the car was running lean, and some misfires. I have replaced O2 sensors (2), ignition coils (4), spark plugs (4) and it doesnt seem to be any better, and it may actually be worse. What is going on here? Please help I am starting to not like this car. Also I have ~65k on the odometer should I worry about the timing belt before the 90k they suggest?

 

Check for vacuum leaks.

 

or try and replace your fuel filter, that can get clogged and stop the flow of gas.

 

no vacuum leaks. would a clogged fuel filter cause misfires? my mechanic seemed to think that the old plugs showed signs that the engine was running rich because it was compensating for the codes saying that it was lean when it was not, that is why we started with the O2 sensors after checking for vacuum leaks.

 

ignition control unit

 

Is the ICU the same as an ICM? I found a link to a way to test the icm, but it seems to be for '99 and earlier cars, will it still work for mine? what are the wires that lead in to the coil pack called?
this one --> http://forums.audiworld.com/a4/msgs/1594531.phtml

 

also how can I tell which sort of A4 I have? I know it is a 2000 1.8T quattro, is it the B5?

 

You don't have an ignition control module.

 

So what else could the problem be? Is there a way to test the ecu? the Air flow mass sensor is different from the O2 sensor right?

 

Can you post the actual codes so that we can look up the causes.