Quote Originally Posted by Audibellybutton View Post
The problem here is your car was running lean for extended periods of time. That’s very damaging to the engine. If you do choose to run E then you should data log to see how your fueling looks. E85 is not the cause of the failure although a tune that is not properly setup for E could definitely cause that situation. You have to flow about 30% more fuel with e85 so if your fuel system is not keeping up or not flowing an adequate amount then you will run lean. I think your tuner should have informed you of this or at least on how to datalog. If you are melting spark plugs something is wrong and you should have reached out to them before allowing it to keep happening. Unfortunately it’s too late now but just for future reference

It puzzles me how you were not getting lean codes though
I agree this was very lean combustion. However this tune is designed for E85 and is an off the shelf tune by IE run by many people and “can compensate for e content down to E60.” I should have been sitting at about E75 during all of this. So this shouldn’t be a fueling issue. Each time the misfire started at 6k+ RPM. But no codes or anything appeared except “misfire cylinder 1” and an EPC light which deactivated the cylinder.

I actually did reach out to IE the first time I had a plug melt. They ask what plug I was running and basically said it was because I didn’t have their recommended in. They did not request data logs or anything. Again I could not find the plug recommendation on their tune page. I’m very happy with the performance and will be sending data logs to them when the new engine is in.

My main concern as well is the lack of codes. At the point a BKR9EIX is melting cylinder temps are WELL out of spec and AFRs are going to be as well yet no code.

Hopefully the root cause can be found to prevent others from having this issue especially considering the price of a used CREC engine.