Hey guys i have a v6 sti that is standard except downpipe back exhaust it has started running badly the issues are from cold it will start and idle fine but as soon as you touch throttle it will splutter and miss fire. When its warm missfire gone but only revs to 4-4.5k and splutters. We have changed plugs and gapped to 6mm and they are ngk 6s. Changed leads, coilpack. There is no cel light on and we have checked for codes and its clear we have also reset ecu. Has anyone got any ideas cheers james

 

I have said maff, does it run any better with it unplugged?

 

Its a brand new maff if unplugged it stalls cheers james

 

Have you put the cat back on?

 

The cat is in yes im wondering if cats blocked ?

 

haha this reminds me of an issue at work where the boilers cut out... turned out we had a dead catterpilla in the pipes lol