Dear R-class owners, I really need your help. My car is R500 '06 with 150 000 km. For the last 4 months I have CEL coming after heavy acceleration, it happens when I come over 5000 RPM. After that it seems like cylinder 1 is disengaged, and if I switch off the engine and turn it on again, it is working fine, although the CEL is still on.
My indy is a very knowledgeable guy, but he's fighting it with no avail so far. All possible repairs were done already, including change of the spark plugs, ignition coils, cables, gas pump, engine mounts, EGR valve, cats, pressure check in cylinders, etc. Everything's good but the problem is still there. I use premium gas so it shouldn't be an issue. It seems we're stuck :-(