Yesterday I went to the store and the car was running great. When I came out of the store and started the car it had a VERY rough
idle. It drove ok from about 2000 rpms and higher and settled out after driven to a ok idle. The check engine light was now on. When I turned the car off, I again get a very rough idle. I had a half a tank of gas so I don't think I got "wet" gas as it did not do this for the first half a tank. I stopped at the gas station and filled it up the rest of the way and put some gas drier in just to see if it was possibly wet gas...no help... This morning I disconnected tha battery to reset the computer and see if that fixed it. When I reconnected the battery I would say the rough idle was worse. Infact I now have a significant drop off in RPMs when the gas is applied...

Any ideas/help

Tks
Peace
Willfulone

 

Don't know.

Engine type, miles, transmission, modifications would help us. We can't diagnose if we don't know what car your are driving.

When was the last time you changed your spark plugs?

Could be a bad coil pack? Could be a vacuum leak.

You will need to pull the code with a Vag-com to diagnose further.

 

Sorry, it's a 2002 1.8T 5 speed with 40000K on it. No mods to date unless you count tinting the windows!!!

Peace
Willfulone

 

Likely culprits are still coil pack or vacuum leak.

Get friendly with someone with a Vag-Com.

Follow the link below.

the link

 

Either find someone that has a VAG COM, or take it to a shop that secializes in Audi/VW and check to see what code(s) it has stored. Once you get the codes, if you post it (them), we'll be able to tell you what they are.

 

If you're still under warranty take it to the dealer. At 40K they change the spark plugs and air filter free.

 

Im having these same problems.....I have an 2003 audi a4 cvt.....error codes P0171, P0300,P0301,P0302,P0303,P0304.....i have gone ahead and changed all 4 ingnition coils...even though two was change last year due to failure....and i changed out to spark plugs with Denso Iradium plugs......I have noticed that ppl have mentioned to check the Vaccum hoses....how would i do that? and possibly clean the TB......my car runs fine......idles rough....at around 800 rpm.....drives smoothly other then that.....any help would be appreciated....thanks