[bcornwellatl]

Ok, so I have a cobb tuned 08 E90 with about 60k miles. Twice now I've gone into limp mode while on the interstate - when I pulled the codes the first time, I received a H code (which I can't find anywhere) and a P code for misfire cyl. 2-

Today, driving back (under 40) I started going into limp mode again - car was spuddering like crazy - got home and checked the codes - had thermal oil sensor code and misfire cyl 2 again.

Now, if I untune the car back to factory maps, it will erase the codes. I have a scheduled appmt with the BMW dealership on the 5th of August. So the big question is should I completely detune back to factory maps and have cobb erase the code - or should I leave it so the dealer can see the codes?

I have a 3rd party aftermarket warranty by Costco - covers everything - but from what I was told by the BMW dealer, they have to perform a diagnostics on the car which is not covered - and I was told if they do not see any codes, they cannot go on my word - they would need to see those codes.

So if I untune and reset the ECU - is there a way for the BMW dealer to scan the car and see the codes, even though I erased them? Or should I leave it? And if I leave it and they update my ECU for whatever reason, is that going to screw up my Cobb maps and if I restore my cobb to factory maps, will that screw up anything the dealer does? ughhh I hate this but hopefully somebody here will have experience or maybe somebody here worked in the garage before and could coach me a bit... thanks in advance..

[E90Company]

When you flash the stock tune back with COBB, all the codes will be cleared so you don't have an option there. It's most likely ignition related (plugs, coils) or injectors. I'd reccomend a plug change if you haven't done it in the past 20k miles anyways.