EPC light came on and car started running poor

[A4 Joe]

Started the car after work and it was idling very rough. Felt like a coil pack issue I had experienced on multiple A4's years ago. I shut the car off, turned it back on and it ran okay but EPC light stayed on. Stopped for dinner with the wife and when I started car up light was out and it ran fine. Any ideas what may cause this?

[bhvrdr]

Hi joe. It can be many things. You could have an air leak somewhere in the emission control chain. Check your intake first but could be anywhere including a pcv on the way out. Of course it can also be anything from a bad injector seal to coilpack. Hopefully there are some dtc stored to point you in the right direction. Get a reading and post it up. Good luck.

Mike

[A4 Joe]

Mike,

Thanks for the response. I have a call into the dealer last night. Will most likely drop the car off today. Don't have a way to log but will post info I receive from dealer. Sure felt like a coil lack fail but was suprosed car ran okay after a restart. I am not sure if coil pack failure is still an issue for Adi like it was 10 years ago. The whole coil pack problem was why I left Audi for 5 years. It really left a bad taste in my mouth as I was stranded multiple times.

[A4 Joe]

Mike,

Thanks for the response. I have a call into the dealer last night. Will most likely drop the car off today. Don't have a way to log but will post info I receive from dealer. Sure felt like a coil lack fail but was suprosed car ran okay after a restart. I am not sure if coil pack failure is still an issue for Adi like it was 10 years ago. The whole coil pack problem was why I left Audi for 5 years. It really left a bad taste in my mouth as I was stranded multiple times.

[bhvrdr]

lol, yeah I used to carry coilpacks around in my trunk...seriously. Let us know how it works out.

Mike

[schirm]

lol, yeah I used to carry coilpacks around in my trunk...seriously. Let us know how it works out.

Mike

Haha me too with my A4.

Good luck OP.

[Nixon_S4]

Busted cat. Pricey repair if not under warranty.

[schirm]

Busted cat. Pricey repair if not under warranty.

2014 I would say its still under the 8 year 80,000 mile warranty.

When I had misfire it was a bad CAT, but would get EPC after a hard pull, would cause back pressure resulting it Misfire. But It can be a couple different things without knowing what the CEL is. But your a 2014 just take it to dealer.

[A4 Joe]

I did not mention there was not a CEL as part of this situation. Car is running strong so far. I talked to my service guy and he said let him know if symptoms reappear and then give him a call. I would rather not have to deal with taking car in for service now so I will wait to see what happens.