I have a 99.5 Audi a4 1.8t and yesterday when I left a friends house to start it it had an extremely rough idle and the check engine light came on flashing after a min it ran like it usually does. But today the same problem I had the codes read but the computer wouldn't connect to my car. Earlier in the weak my colant was pretty low for some reason but I had roped it off with g12. I've parked the car and won't drive it but want this fixed as soon as possible. Any and all help would be greatly appreciated

 

Search function will tell you that a flashing CEL means you're actively misfiring. Gotta get the codes to see which cylinder is acting up.

 

Had the codes read misfire cylinder two and bad throttle position sensor/pedal sensor?? P0123

 

check your ignition control modules

 

module since its a A4

 

swap the coil pack to a different cylinder and rescan for codes. If the misfire follows, you know your problem.

BTW, do not drive with a misfire, you'll destroy your cat.

 

Thnx for all your help guys I'll pick up coils tomorrow anyideas on the throttle position sensor/pedal sensor?

 

Yes it's all to do with the cold weather, there are quite a lot having similar problems, it's most likely your cars timing,

 

Do a throttle cleaning and adaption and see if this helps.

 

So far I have replaced the ignition coil on cylinder two and the car was running fine until I left work tonight now it's running rough again and the check engine light isn't blinking now. I'll have the codes read again tomorrow