audi 1.8 turbo

having the timing belt one tooth off on a audi a4 1.8, wouldnt that cause a check engine light to come on, so far one hasnt came on but the thing seriously has no power.

It may or may not set a trouble code if the ECM can compensate for the timing problem by advancing/retarding the spark timing....within the range of its programmed maps.

I'm assuming, based on the question, that you just changed the timing belt. Did the vehicle have low power before the timing belt change and that's why you suspect it's a tooth off, or did it run like this before as well? You might have this thread moved to the Audi A4 forum as the regulars there probably have a few more specifics on the car and tricks to changing the timing belts to watch out for.

Other than the lack of power does the engine seem smooth and idle decent?

-Rod

Spark timing wouldn't help the situation very much since it would actually be a problem with mechanical valve timing. Depending on which way it is off, you gotta figure that for every tooth that the cam is off, it would put the cam anywhere from 5 to 10 degrees out of time. Not sure how many teeth are on the gear(s) on the 1.8 but if you think the thing is out of time MAKE SURE IT ISN'T. Unless the PCM is setup to specifically monitor cam/crank timing, the only codes it might set are misfires and rich/lean conditions. You could do some serious damage if you don't do anything about it asap.