i have a 2000 audi a6 2.7t 6spd.When im driving it sometimes it misfires . almost everytime in a high gear like 4th or 5th pull. Sometimes the check engine light will flash then go away.. i got the codes checked out.. it was mis fire on cylinder 4, 5 and 6. and a code for exhaust gas temp sensor and exhaust gas temp. ive been told it could be coils.. mass air flow sensor or the exhaust gas temp sensor as the code says. Does anyone know for sure what it could be?

 

The fact that the misfire codes are for the whole left bank of the engine would make me think it's not the coils. It is possible, but not probable that all 3 would fail on one side at the same time. Same for anything common to all 6 cylinders (pretty much any sensor) would not affect only one bank. The exhaust temp codes are because the exhaust temp is over limits due to the missfire. The sensor is most likely just fine. You could have a cam adjuster problem which would effect one bank, but not normally cause a "misfire" condition. Because of the exhaust over temp, it would seem it's an ignition problem. Suppose the easiest thing for a quick check is to clear the codes and swap the coils from one bank to the other and drive the car until it acts up and the CEL is on. If the codes are for cyl 1-2-3 then it is coils. If it's still for 4-5-6 more digging is required. I assume the codes were P0304-5-6 correct? No ignition circut codes or anything like that? Hope this helps you out a bit.

 

If you have a code for the EGT sensor, and its for bank 2 thats the problem.
EGT sensors can cause all sorts of problems with the engine management when they malfunction. Always address the fault codes at hand before diagnosing further.
Once thats done, if there is still a misfire then diagnose the misfire issue by swapping ICM's (ignition control modules) and coil packs to try and pin point the miss.