Boosted Falcon

hello all,
i have an ef fairmont and the car doesnt rev past 4000rpmon gas or petrol when on full throttle...tried map sensor, 02 sensor, has high flow cat n 1 muffler installed about 1 year ago, when does happen engine sounds like its pingin on gas (very rattly) any1 came across this, any help would b appreciated

thanks steve

Throttle cable maybe?

nah mate

Dude, your accelerator cable WILL be stretched.

nah mate it goes past 4000rpm when goin lightly on on throttle it only happens when full throttle

fuel filter, ignition timing, fuel pump, fuel pressure reg, blocked cat, smashed valve...........