ok, so i bought an 02 with 62000 miles on it about a month weeks ago. I was driving it about 3 days after i bought it and noticed the CEL had come on. i took it to the guy i bought the car from and he has a mechanic who that works with him and he is the head mechanic at the local audi dealership. the cel is a random multiple misfire. it ended up being 4 different cylinders. he hooked it up to vag com diagnostic tool and he then tried spark plugs and coil packs and ignition control module to fix the issue. neither worked... any ideas???? Also, could this misfire cause the engine so vibrate very lightly at idle and could it also cause the engine to kinda bog down when i turn the ignition off, i just doesnt sound very smooth when it turns off??? help!!!!!!! My car has had a CEL ever since i bought it basically

 

No S4's have bad turn off they all sound like they are almost stalling out when they are turned off, as for the misfire codes.... idk i do know that alot of people live with some misfires

 

1. check your spark plugs
2, test the coil packs
3. test the MAF
4. Test the CTS
5. Test the coil amps
6. Test priamary O2's & EGT's

If you do not understand any of this, purchase a Bentley & Vag-com, you will NOT be able to fix it with out both of them.

 

From what you've described it sounds like it may be slightlydieseling when you shut it off.

Don't assume misfires are only caused by the ignition system. Look into the fuel system also.

A bador leaky injector or bad injector signals can cause dieseling typesymstomsand misfires.