Rite guys I've installed a Harvey uppipe and ported headers with a decat downpipe car runs fine , then engine light comes on and can't rev pass 4k revs . Oh my speed sensor is broke so I don't think that would cause that .

Oh I did have standard headers and sports cat downpipe with decat uppipe before

Has been mapped before fitting of the new items

 

speed sensor will be causing it to stop reving past 4k because the car thinks its sitting still.

you need to remap for the decat and headers as the previous remap is now useless as its now going to be overboosting.