hi i have a d15z1 block with a d16z6 head. P28 ecu, d16z6 timing belt.
it only revs up to 5000 rpm
it is boosted with 6psi. i don't have a downpipe, so exhaurt gases come right out from the turbo. the o2 sensor is pluged, bolted on exhaust. since i don't have a downpipe.
please help...

 

redline is determined by your ecu. P28 is 7200

 

i know but it doesn't rev over 5000 rpm

 

Well, I'd start by getting something welded up as a dp and get that O2 in there as a start. Any CELs?

 

check the CEL's. idk much about diagnosing things like this so hopefully someone else will.