2001 A6 Avant Quattro occasional rough idle
 

Hey everyone so lately my A6 has had a random rough idle. Like its fine at one traffic light and when I hit the next red light it starts to run rough and the rpms dip down slightly but as soon as the light turns green it smooths out and stops running rough til maybe after 2 traffic lights. Doing some research on here pointed to the throttle body being dirty. I changed the spark plugs last week and even tho that released some lost power the random rough idle is still there. Just asking your opinion before going in and start taking things apart cuz it's not all the time that it runs rough.

2001 Audi A6 quattro 2.8 V6 175,500 miles

Thanks

Usual suspect in this case: Vacuum lines/leak

The occasional dip down while standing could be the alternator kicking in - at least in my case it was. I had a dieing battery (without knowing) and the alternator had to kick on every couple of minutes to compensate for the battery losing charge. Unfortunately I didn't notice this until the battery died completely and took the alternator with it (probably due to excessive load).

One thing I have never done is disconnect the MAF sensor nd cleaned it. Would it prolly help if I cleaned it??

My 99 A6 had rough idle and the problem was Vacume lines were no good so I bought 8 ft. Of line and replaced everything. Also bought the PVC hose cuz that was cracked and rigged up with tape and heater hose.

u pull out codes?

@ kikin: a couple months ago I had a code pulled (p0430 i believe it was) BUT It wasn't running rough. I had it cleared for smog check here in California and passed with flying colors. I haven't put it to the scanner recently tho