KF TX3 big loss of power, Need Some Help!

[XCSEDAN]

maybe you guys can help us out,

me and a mate were driving round in his KF TX3 (N/A) FWD, we noticed a SEVERE power drop, im talking a good 30KW (at the flywheel), won't rev past 5000rpm, and has dropped about 15db in exhaust noise.

At first we thought it might have been because the cat was gone, (it was well and truly stuffed and we knew that), so we put a broomhandle though it and cleaned it right out, it made a tiny difference but bugger all really.

so then we thought it might have been a bad batch of fuel (from 7/11), so we went to another servo, filled it up with BP Ultimate... made no difference.

we havn't yet done a compression check or taken the car for a spin without the pod filter off (to see if it blocking up some how), or checked the fuel filter. we ran out of light to quick and it was also raining....

just wondering if any of you guys could help us out... we cant seem to work it out, the next idea on my mind is that there is a blockage in the exhaust (due the massive and almost instant drop in exhaust noise) but we haven't had a chance to pull the entire system off yet and probably wont until next weekend.

just to put into perspective how much power its lost, when we tried to spin the wheels in the wet (trying to see how bad the problem was) it barely spun, it only spun up to about 4000rpm in 1st gear! now usually it will be all wheel spin until it goes into 4th.

help please?
cheers