so like a month and a half ago i blew my turbo up. i decided to go with a k04 kit. i got it, installed it. got the ecu reflashed. the check engine light is on because of the test pipe i installed when i put the new turbo in. but the car also shows a p0304 a cyclinder 4 misfire. how do i correct this. i have new sparkplugs to put in i havent had the time yet. is there anything else that it could be?

 

bad #4 coil pack, dirty fuel injector.

when was the last time you changed the plugs and what plugs did you use?

 

i just changed the plugs yesterday before that i never did. it got better, but its still not right like if i want to boost i have to be at high rpms. and if a coilpack went bad wouldnt it just not work ever cause its only when it boosts at like low rpms.

 

do you have a boost gauge? what is the idle vacuum reading? you could just have a leak somewhere.

how high do the RPMs have to be?

 

vacnuum is like 14 i know its low. i cant find the leak anywhere. and itll boost like 5 pounds easy anywhere in the rpm range but anything higher than 10psi it has to be like above 4grand. and when it hits 15 it misfires like crazy.

 

look around under the intake manifold, theres a few hoses that like to crack that normally you cant see. it could also be one of those many check valves that are all over the place. a leak is most likely your problem, whether or not you can find it.

 

gap the spark plugs if you didnt.....but sounds like a boost leak

 

they were gapped. but alright guys thanks. ill have to look around.

 

swap #4 coilpack with #3 and see if the misfire follows. it's most likely the vacuum leak that's causing the problem. you vacuum is a little low but not terrible, still need to be fixed though. if you have vag com, it can logs misfires even with the free software