Check Engine Light After Chip Install

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2002 B5 S4 45xxx

I need help figuring out what this is before I take it in, if I do...

My engine light came on and recieved the following fault code when scanned. I had hust had a temperary APR Chip Upgrade Installed. For all who dont know, its basically a trial version good for 6 hours so you can love the result and spend the $600 to buy the permanent one.

Fault code 17585 "Bank 2 lamda correction downstream of Catalyst; control limit attained"

I had the code cleared and the temp chip has expired. The check engine light has not come back and it has been 2 days.

Can anyone help me figure this out please? Maybe bad cat? or o2 sensor?

 

sometimes the ecu will correct whats wrong and if your check engine light doesn't come back on then your good.

if it does i would guess the 02 sensor or a boost leak.

 

I got a CEL last night too...actually, I'd gotten a CEL a week before I sent off my ECU to be tuned, but I added a couple of spark plug non-foulers to the rear O2 sensor and within 10 miles of driving, the CEL went off.

Sent off my ECU...got it back on a Friday, and then last night (Thursday), I went to start my car...took 3 times to start it, and the CEL stayed on once it was running.

 

just to let you know for future reference, there is a section for S-cars... they can help you out alot better than us A4 guys...

 

if the code doesn't come back, your fine. maybe the chip made you run too rich and caused a carbon build up that has since gone away. if it comes back, its probly the cat or maybe the sensor. if you had an o-scope you could check the sensor

 

My bad for posting in the wrong section. I saw B5 on a link and clicked it and didnt realise this was the A4 section till the next day. By you guys have actually been more helpful, thanks!

 

Glad it's paying off Several other S4 guys post in here a lot and overall there are enough similarities that for most of your problems, the A4 section will be able to help.

BTW, I agree that if you continue to see the code it's likely related to your driver's side post-cat O2 sensor.