Hi,

Last couple of first starts of the day I get a fairly rough idle when in fast idle and a flashing CEL. After it warms up it idles at the normal level but after about 10-15 seconds of that it starts to get rough again.

Is this caused by O2 sensors on their way out? If so, which one(s) usually go bad?

Specs: 2001 A4 1.8tqm 110,000miles.

Thanks,
Mike

 

Flashing CEL usually means a miss fire. Get the codes read and report back when you've got them.

 

if the problem with your o2 sensors, the pre-cat o2 will cause the car to run bad. the post-cat sensor is just to check the efficiency of the cat and doesnt have any input on how the engine runs.

 

Rough - just the way your mother likes it, Trebek! HAHAHAHAA!!

 

I'll take The rape ist for 600. That's Therapist Mr. Connery.

What the weather like where you live? Very very cold or what?

-Joe

 

lol i was going to post that but figured it might be offensive if the OP hadnt seen the show.

 

UPDATE: I scanned the car and had a misfire in cylinder number 3, changed the pack and all is well. The cause of the rough idle was oil on the tip of the coilpack, I need to change the valve cover gasket, it leaks into the holes where the sparkplugs are.

Thanks guys,
Mike

 

^^Awesome! Glad I could help...