AMG__Dom

Hey guys I have a 2005 CL 55 I've posted in the W215 forum but there isn't much traffic hopefully I can get some more input here.

My car runs and drives completely normal and effortlessly under regular conditions (driving like a normal person) but under WOT it will start to misfire from about 4-5k + previously I would just let off the gas and the car would be fine. Now once it misfires it stays misfiring until I shut off and restart the car then everything is normal once again.
I've scanned the car with STAR and it first said Cylinder 1 & 2 misfire, cleared the codes got it to throw the CEL again but this time cylinder 2 & 3 nothing about cylinder 1.

I've already swapped coil packs, I've purchased spark plugs and wires to swap next. But i'm starting to think its fuel related more than electrical.
Any ideas? running some chevron techron injector cleaner right now and was going to grab a new fuel filter as I've heard its pretty common to get clogged, also read it could be cats but I have documentation of the previous owner replacing both of them.

Any help would be greatly appreciated, thanks! - Dom

Dr Matt

I think you have a good plan, I'd see if the filter fixes it before digging into anything else. If it is restricting fuel flow, upper RPM at WOT is where you will have problems first and it will get worse over time. Cats cause a loss of power more than misfires.

AMG__Dom

Thanks for the quick reply! actually meant to post this in the general tech talk but thanks! will be giving it a shot tonight, will post results tomorrow