hi justin, I have the car, dealer said they checked every item related to bank2, plus while hooked up to the computer the get an over view of all readings, they said car is perfect, they feel that it maybe a sensor going bad but throwing the misfire codes before the problem sensor throws a code, ie 02 sensor
Well I happy that I finally fixed the rs4 misfires, I hope this helps anyone in the same boat, if you read all my diagnostics i went through, you will find I tried everything, I spent a couple of thousand on the car in and out of the dealer, The car would only throw misfire codes on banks 2, I put new 02 sensors and it fixed the problem, what Im told is that the car would go into misfire codes before o2 sensor codes, Im hope this help anyone, DONT goto the dealer, as nice as they were, they could not figure it out…
Good of you to return to the thread with an update, thanks!
Rock so great to see this was fixed. If you can please help with this question. 3 of your posts said the dealer checked the 02s and said they were fime…obviously they were not fine. How was the dealer testing the 02s and did you just replace the 02s on the theory that the 02s will throw miss fire codes before bad 02 codes or did you test them and find them bad.
Either way it’s awesome you got this cleared up.
Hey Justin, dealer said they checked the 02 sensors via what they call a ( readiness code ) when plug into the dealer computer at normal running temp. Bottom line is the readiness code is not accurate and the 02 sensors could tell the diagnostics computer that the 02 sensors are ready working when in fact the 02 sensors are on there way out. Ready code is good for 02 sensors that are completely failed. Hope this helps!!
Interesting.
So they probably ran the basic settings test between channels 30-39 and 43-44. You can do the same thing with a vagcom if you know the procedure.
It is interesting. I just wanted to see what they did. Sounds like they just pulled up the readiness check and didn’t actually put them through a test.
A note to those searching this topic (Yes, I realize this is an old thread): We struggled with a very similar misfire and came across this thread, leading us to examine the O2 sensors. We found that (at least some) Audi dealers are now selling sensors that have plugs than can fit into either left or right connector. The OE parts had connectors that were different left to right.
After doing a clutch/flywheel job, our tech inadvertently swapped the sensor connectors on reassembly. Since the first one went in fine, he figured he had them right. Well, he did not. The left bank ECU was reading the right pre-cat O2 sensor and vice versa. No codes other than misfire, so we had a hell of a time sorting out the problem.
When we went to order a left side sensor, we pulled the connector to check the shape to make sure we’d get the correct one. This is when we found that they were both the same, unlike the original sensor connectors, which were geometrically different.
Swapping the connectors fixed everything – eliminating the misfire codes, CEL’s, Traction Control light and occasional EPC light. I don’t expect this would happen when changing only one sensor, but very likely to happen with the newer sensors (if Audi dealers are actually selling the correct ones) if both are removed without tagging them ahead of time. Buyer beware.
Chris