Nate Alfano

99 A4 Quattro 2.8
Auto Trans

So the Sputtering seems much more prominent when the engine is running cold and accelerating from a complete stop through 1st-2nd gear (seems to stop once above 15 mph) Once the engine is warm it is very seldom but does still happen at times. There is only sputtering upon acceleration, driving at normal or highway speeds there is no issue.

The check engine light came on and was reading p0303 (cly 3 misfire) and p0411 (Secondary Air Injection System Incorrect Flow Detected) that was pending. I cleared the codes and took it for a ride and the check engine light did not come back on but the sputtering is still there. Checked codes again and now no codes are coming up but I'm sure that won't last for long.

clancy

Is this a cold engine only issue? Or does it happen with a warmed engine as well?

No other codes? After a few drive cycles?

Nate Alfano

Yes it is only when the engine is cold. When the engine is warm it does not sputter from a stop and drives fine.

No other codes and still not reading any codes since I cleared it, but it is still sputtering when cold.

Nate Alfano

I wanted to edit out in the original posting and put it is ONLY when the engine is cold.

It does not sputter at all once warm.

Nate Alfano

So I just took for a long drive and wanted to clarify (this is actually my moms car)

There is ONLY slight (but very noticeable) sputtering from a complete stop upon acceleration to 10-15mph and ONLY when the engine is cold, once above 15+mph there is no issues at all, it is literally only those 2 factors congruently (engine cold, initial acceleration from stop)

There is no sputtering at all while idle and the car never comes close to dying out, once the engine is warm there is no sputtering at all.

clancy

I would suspect your coolant temp sensor. Sometimes a code is set, but not necessarily. Mine is intermittent and if I try to drive right away with a cold engine it hesitates badly and sets codes for other things, like a miss in one or more cylinders. If I simply do nothing, meaning let it idle (poorly) for a minute until it settles then it drives fine and does not set any codes. Or, if I turn it off and restart, then it idles fine. I will change my CTS one of these days. I'm a little peeved as I replaced it just a couple of years ago.

Easy and inexpensive fix, if that is it. If not, you probably would have needed one soon.