2004 A6 2.7T dealer report question.
 

I recently took my car to a dealer to get an inspection done to figure out what was wrong. (answer: many, many things) I am trying to see what issues I can fix myself, to save money. One of the things that was reported was as follows, "multiple faults found in ECM for misfires and rich condition." Does this mean that the ECM found faults with the engine, or that there is an issue with the ECM which is causing those things to happen? This was under the report for the check engine light, and the other reasons for this were a broken coolant temp sensor, and a vacuum leak on a check valve. (I don't know which check valve it is, there is only one vacuum line which has two check valves, so I'll just order both to be safe. If there is more than two check valves that have a vacuum going through them, let me know.) This car was my Dad's, and he got a chip tune or whatever it is called shortly after he bought it in 2004, and for at least 10 years it was all fine and dandy, but then everything went downhill. I can definitely feel the misfires, however they only happen at idle. Any help about what is wrong and how to fix it would be appreciated.

Well... for starters this car can be very difficult to work on and diagnose. The faults are probably not being caused by the ECM. The vacuum leaks could be causing most of those issues. And the coolant sensor will need to be replaced/ inspect connector as well. Under the Y pipe(on top of engine) is a few vacuum lines and check valves. take them off and test them multiple times! you can just blow through them one way only. behind the engine on the firewall side are more vacuum lines and t's etc. check all those too. Use a flashlight and small mirror if necessary.

That or sell it and buy a 1.8t. Much better starter car to work on.( you won't want to kill yourself)
good luck

Thanks for the info, I finished a bunch of repairs (entire front suspension including axles, rear struts, and one of the valve cover gaskets, and some vacuum stuff, and the coolant sensor. Made sure it was secure, it popped off once.) Hopefully the check engine light doesn't come back on, Ill report back to see if it does.

Nice! Good luck