I have a MY99 with TEK2 and full decat. Have been noticing intermitent power levels lately. If you drive along gently for a while and then put your foot down it will sometimes be really flat if I then contine to keep giving it some wellie with a couple of standing starts its fine and all the performance comes back. Once the engine/tubo has got really hot its always reliable performance but start driving softly again for a while and loss appears again. One thing I noticed last night after having a reduced power spell is that the idle had crept up to 1500-2000 rpm gave it a couple of standing start in 1st 2n 3rd and powers back and correct idle....Strange. Anyone have any ideas...thanks

 

Could be "MAF" sensor playing up, does the idle speed go lumpy as well, or any faltering when slowing down for junctions?

 

Had few idle problems a couple of weeks ago but o.k now. It also seams to have the same problems if you hold the revs at say 3000-4000 and floor it in 2nd and 3rd. I was wondering if the lambda had anything to do with it. It looks pretty ancient and like its been in there for a while..