# 2000 Audi s4 misfiring



## wrknkm (Oct 25, 2009)

I have a 2000 s4 and it is misfiring on one cylinder. After the problem occured I put new plugs in it and its still doing the same thing. I drove it 20 miles and it ran fine, shut it off for 15 minutes, started it and it was misfiring the whole drive back. Sometimes it will run fine and other times i'll start it and it'll misfire. I Don't know where to start so any help would be appreciated. Thanks.


----------



## nikitynick (Jan 14, 2007)

*Re: 2000 Audi s4 misfiring (wrknkm)*

have you pulled the codes yet?


----------



## gdtech (Apr 11, 2010)

*Re: 2000 Audi s4 misfiring (wrknkm)*

you need to scan it and see which cly is missfiring then swap coils with the cly next to it to see if if follows the coil if it does its a coil if not try swaping the power output stage there is one for each bank and there on the top of the airbox if the misfire goes to the other bank then its a output stage. if not then check compression some times 2.7t burn valves. if that is good u can also swap inj and see if it follows the inj.


----------



## jettasmooth (Aug 7, 2002)

*Re: 2000 Audi s4 misfiring (gdtech)*

most likely the power output stage (ignition control module) thats mounted to the airbox. Usually the main cause of misfires in the earlier ignition systems. The coilpacks are pretty bullet proof. As mentioned above, find out which cylinder is misfiring, then switch the POS wiring and see if the misfire transfers to the other cylinder bank. If it does, then its a bad POS.


----------

