Ok lads, thansk for the advice.

I am going to diagnose tonight and try get some error codes for you.

I have the boost controller completely off at the moment, so tha car should be running 7ish psi, which is the cold boost pressure on a standard mr2 if i am correct? Yet it creeps to 10psi.

This has onyyl started since fitting the exhaust.

Itit was actually fine for the night when i fitted the exhaust, then the engine managment light came on, and it started this.

I can drive the car slowly and carefully to and from work with no engine management light.

When I go to put the foot down, or the revs go past 3k, the light comes on instantly.

Regret fitting the exhaust now as the car ran fine with the old stainless duplex system