hi all, i hope someone can help.

my '99 a4 z-28 has been running a little rough lately. when the car starts cold, it will run fine 'till the engine gets up to "operating temperature" (where the temp gauge usually resides during normal use) and then i get a rough idle and rough running.

the idle isn't always rough though... sitting at a light the engine will idle smooth then shake a little, run smooth for a bit and then shake a little, etc... also, when cruising around with the a4 in top gear and the tc locked, i can give it a bit of throttle and it sounds like i get a miss, sometimes. wot doesn't seem to be affected.

i was hoping that the car would throw a ses light so i could get an error code and, fortunately enough, it did just that on the way home this afternoon... the code was 0410 (secondary air injection system malfunction). i have absolutely no idea what that means. is this code directly related to the rough running, or could it be just a symptom something else?

the car has a gms maf and the free ram-air mod, but has had those mods for well over 5,000 trouble free miles 'till now. i don't think it is a bad tank of gas, because i ran the old tank almost all the way out and filled up with a different brand 200 miles ago and the trouble persists.

any ideas?? thanks!

jay
san francisco

 

im 90% sure it has to do with that but i dont know how to fix it


it makes sense that it would idle weird

 

I got the same code but ebverything runs fine, did you ever find out what it was(code 0410) 3 years ago?

 

turns out that the rough running was a bad plug wire.

the error code problem, however, was never solved. i replaced all the major components in the secondary air injection system save for the air pump itself and the car still threw that code randomly. i wound up have the code deleted.