Originally Posted by Nevers

So I took the 370 to the dealership because of a P0305 SES light.
(Cylinder 5 misfiring). I just got a call from the technician, he asked me what kind of oil I am using and when I installed my Stillen Gen3s.

I told him November for the install and Royal Purple for the oil.

He informed me that Royal Purple is not ester oil and can/will **** up the cylinder heads.

Is this true and what am I facing now?

IF things are damaged am I responsible and/or void my warranty. Im waiting for him to call me back after he looks into it further.