ver heard of a timing chain setting off a CEL, unless it broke, then it will set it off. there is a possibility of chain slap causing it to set the CEL, not going to rule that out one bit. and he's right about the derive time if your car is OBD2 or 3,being an 01 it will be OBD 2, which sucks worse than OBD1 and I'm sure OBD3 is going to be even worse, you can thank congress for that crap. the others are right about getting the codes cleared, but you still have to drive it on both city streets and freeway to get the OBD 2 to reset itself, along with clearing the codes. have fun with that.

Hold your breath if he did such major repairs and didn't even own a scan tool.

It will eventually reset if problems no longer exist, but take to autozone or some other free code retrieve place and see what code it is, it may indicate something is not done right, and by the time you notice this guy is down the road with your money.

If it was a fault that could be reset it should have cleared while the battery was disconnected for the timing belt or chain replacement. Swing by autozone or advance auto and ask them to read it for you if he didnt have a scan tool to clear the code then he didnt know what the CEL was for at the start of the work. I would not trust him 100% either.

I'm not sure why a light would come on for a timing belt anyway. Get the codes read again, just to be sure

I don't see any way that the computer could tell could tell the belt was going bad. They don't degrade or stretch, they are either 100% good or 100% gone.

Anytime the check engine light comes on,a code is stored.Even if the cel goes off,the code still needs to be cleared by use of a scan tool.The cel should go off as soon as the repair is done and the code has been cleared.If an emissions related part was replaced,the KAM(keep alive memory)must be cleared.This is done by disconnecting the neg battery cable for 5 minutes.The vehicle must be driven at least 10 miles after this is done so the computer can relearn needed correction factors for all sensors.Driveability problems may occur until the computer resets the adaptive factors during this drive.Don't disconnect battery if a emission part wasn't replaced.If the timing chain was causing a knocking noise,this could have caused the knock sensor to store a code implying that it detected detonation when in reality is was just noise from a loose chain.The code would still need to be cleared too though.

He obviously didn't have a scan tool to erase the code. Bottom line, if the code has to do with the timing chain and he did it right, it'll either go away or it won't. You'll know pretty soon.

Guessing isn't going to get you anywhere.

Will the CEL go away on its own after a timing chain replacement?

Car is a 2001 Volkswagen Jetta VR6 12v.. The independent mechanic who did the job told me that it would.. He said it would take between 1-200 miles for the 'computer to reset itself'.

I'm not sure whether to believe this since the guy took forever to do the job and bungled a few things along the way. Obviously he knows a lot more about cars than I do, but I don't trust him 100%.