Brother acquired a 12' n14 jcw and half the time he goes full throttle it throws a cel/limp mode but no codes and I've tried numerous scanners with no luck.
I did notice it had NO sparkplug guide tubes so he's ordered those. Could that contribute to the issue ?
it has new but with no changes, aluminum valvecover, sparkplugs, noise maker delete , cone filter and forge bov. Along with oil change and coolant flush.
intake isn't cracked , i didnt see any unplugged vacuum lines or anything..
any tips or suggestions ??
Any help is always much appreciated

 

Spray some water or starting fluid over the vacuum lines/intake and double check all intake/intercooler/throttle body piping. If nothing is immediate, check the vacuum lines and air tank under the throttle body. This is usually what caused the issue for me. If not air, double check fuel volume and pressure and then look at spark plug tips and go from there.

 

the plugs I removed DEFINITELY were running lean , which I'd think would lead me towards a vacuum leak. I'd think a fuel pressure code would atleast throw a few error codes atleast it did in my experience.
but good idea with the spray.. I did check vacuum pump line , wastegate line , intercooler hoses and the intake also for cracks and all was ok. Buuuuut I didn't really check the purge valve lines and canister lines.. I did feel if the pcv hose was cracked but it felt ok..
I will be smoke testing it very soon next time he can get it here and I got plug tubes too for him now.

 

Plug tubes replaced with no change.
I smoke tested it and found no vacuum leaks either..
I do notice a squeaky type noise from down below intake manifold, could it be a faulty throttlebody and thats possible the noise in the video or possible a bad pcv ?? Through I can't imagine the stock pcv amd new valvecover both having bad pcv's..