Last night I decided to see what my max boost is, and I went all out in 1st, 2nd and 3rd (ran out of room afterwards ). Using the stock gauge, I noticed that the car wont go beyond 0,3-0,35 bar (we are talking WOT here), and I think I noticed difficulties at high revvs (like the engine was straining to rev higher, above 6000). The car is due for an ATF and some new plugs anyway, so this could be it, and I also think that the precat must go to catalyst heaven, but is there any other reason ? Anyone any ideas ?
Any help greatly appreciated, blah blah blah...

 

Possibly. Recently overhauled my firsts turbo. First turbo experience. After break in, noticed the factory gauge would go almost to the last bar. Then a few weeks later noticed how it would go close to the last bar and then drop down a bar. Got where it would not go as high as what the day before was. Got Autometer gauge. Would only pull 3psi at best. Took an expensive guess and ordered a downpipe and presilencer from Mazdatrix. It now pulls 7 and 3/4 to 8 psi. Suspect the cat was bad. Ain't gonna put it back on to find out. Hope yours is the same type problem.