I have an 2004 A4Q 6spd 1.8t, I have changed all four coil packs, service regularly, but still am having a problem with stuttering when under hard load and more than 3/4 throttle. Have no idea what could be causing this.
The air bag light comes on intermitently and then goes off, dont know why. any help would be greatly appreciated.

Thanks
Stephen

what shop have you been taking it to...

also what coil pack did you change

Any CELs? If so is it flashing? Get your codes read at autozone (free) then post them in the B6 area otherwise people are just guessing as to whats wrong and thats really not alot of help. Sounds like a misfire but can't be sure w/o codes.

yea and if it is a misfire it could be one of the spark plugs that OEM had manufacturer flaw and got recalled

sorry its been awhile to get back, I've changed all the coil packs, bought them at Autosport Werks. Changed all the plugs. The code was for the small emission leak, the valve on the passenger side of the engine, changed that. The next thing is a Timing belt change, I guess I'll do it myself. Many years working on cars just never on one of these, if it was domestic I could tell you.