well this problem has been getting worse and worse then all of a sudden my check engine light stays on and says i got bad cataylic bank 1 and then while driving my engine suddenly looses power as i round the corner and a epc light comes on i suppose this is the Limp Mode coming on. next few days i dont drive it and I go back to try to start it and it wont turn over it just keeps cranking. I thought maybe its the battery jump it and still nothing. then i change the spark plugs and still nothing not wanted to change the coil packs yet i pull start it cause it a manual and it starts as long as i drive it daily and dont let it sit for more than 10 hours at a time it will start but hard. any how how can i tell if its the coil packs going bad? i dont want to buy all of them and find out its still not that. it miss fires if its idle and you are sitting in the car you can feel it mis fire but only once in a while its not a constant misfire do the ecu will not recognise it as a bad or faulty coil pack. so it wont tell me which coil pack it is. one of the mechanics i had talked to told me that he checked it with some tool and it was idling at 20 hertz instead of some other hertz and i didnt know what that meant i just shrugged it off and paid my 150 for the coolant elbow gasket replacement that sits behind the head right next to the firewall. If any one knows how to test the coil packs or what not let me know. The car cranks but wont turn over when its cold and it starts up when push started. runs fine after wards and turns on and off ok after it has been push started. if you think i should just buy the coilpacks anyhow or if you have some solution or knwo what the EPC light does let me know email me or post on here brotzvang@hotmail.com

 

Reset the codes and recheck them.

 

well i just bought four new coil packs and put them on it started but ran really rough. I had the epc light on which reading through the manual says its in limp mode so i went to autozone and they let my use they scan tool to remove the codes and everything was fine. it started up decent and no running problems or codes came back. the only thing i read in one of the audi TSB's was to use top tier gasoline to stop it from getting too much carbon on your injectors and what not. i let the car sit for 5 hours and went back to turn it on and it was still starting really hard took at least 7 secs of holding the key to get it to turn on. i drove to autozone picked up a bottle of 16oz Sea Foam and threw it into the gas tank and filled it up with 93 octane gas (Top Tier) from Kwik Trip and ran it for 30 min on the highway and let it sit idle in my drive way for 1 hour. turned it off waited 5 hours and it turned on with in half a second of the key turning so i had alot of things going on at once for this problem. one, the misfires were random causeing excess fuel go into the cat causiing it to say it was bad catalist instead of telling me which coil was bad, two, the coils were getting bad but it didnt tell me which one. and three it went into limp mode when it finally failed on me. so Changing the plugs and coils-on-plugs with fuel system cleaner helped it alot using top tier gas also helps. i was using BP for gas but now ill be at Kwik Trip or anywhere it says top tier

 

my car stopped working again even after changing so many things like the coils, plugs, fuel filter, fuel pump relay, and now im working on the engine speed sensor or now audi calls it the impulse sender unit for 70 bucks at the dealer part number 078906433a ill post back to see if it works or not

 

just realized how old this thread is

 

Dude, crank sensor, get a Bosch one, had the same problem.

 

If not that it's a cam position sensor. Which is more than the crank sensor so start at the crank sensor. Also try push starting it if it just turns over, bet it fires up.