ok guys heres the issue(s). i have the 1.8t aeb engine with a manual transmission so you know what im working with here.

when i got the car it was bone stock. over the past year ive installed:
fmic w/ hard piping
aftermarket intake w/cone filter
1.5" TEIN sport springs
few visual mods

nothing to fancy.

so i got the car tuned by NA Motorsports in clifton park NY and had a stage 1 plus done, and when i bought the tune i also got a boost gauge and steering pod for it also.

i was told the tune has it set up to run 18psi... WELL! since i got it tuned at around 3500rpms i get a spudder and the boost gauge only says between 5psi to 10psi. sometimes it will give me 15psi but it never stays consistant. i figure boost leak. reading a bunch of forums i started to replace parts that were associated with other peoples similar problems. below is a list of what has been changed out for new parts:

MAF sensor
ICM
all 4 coil packs
all 4 NGK spark plugs with .032 gapping ( old ones had .042)
02 sensors
new fuel fliter
new fuel pump
new injectors

i had it re-flashed and re-tuned and still doing the same thing. i checked the turbo and it has no broken fins and no shaft play. the turbo is OEM and the engine has 166xxx miles on it.

my buddy sold me a chinese turbo some K04-05 that he told me to drop in and see if that fixxes the issue, but before going through the headache of doing the sway i wanted to ask you all what you thought.

some one help me!!!! its driving me wild, and i was daily driving it... now im asking for rides to work.

 

oh also when it spudders the CEL flashes and then stays on, when i plug in a code reader i get a cyl misfire. when i clear the code, and it throws it again it says a different cyl... so far its told me cyl 2 than cyl 4 than cyl 1. im hoping i dont have to see cyl 3!!

 

Are you running OEM injectors? With most Stage 1+ tunes you are required to upgrade your injectors. Also, what software did you have flashed to your ECU? Or was this some independent guy that flashed his own tune to your ECU?

 

Forgot to ask earlier, but do you have any other codes?

 

Unitronic tune stage 1 plus. i was told the injectors aren't oem, that they are bigger for the tune/ko4.

i got anoyed so tonight my buddy and i started to take the stock turbo out, and install the new one... turns out prev owner had a leak on the downpipe and jbwelded it... now the the last part of the dismantle the LAST!!!! nut is jb welded onto it, and i cant get it off... its like banging my head against a wall.....

 

no other codes

 

#1 I am very surprised jb weld held up to exhaust temperatures. #2 Question is which bolt is jb welded? One to the turbo, or one to lower exhaust? If it was the lower one you could possibly remove the pipe clamp a little further back on the exhaust, after the flex pipe section. Slide all of it out that way. Or if it was one connected to the turbo, just unbolt turbo from the exhaust manifold and pull up and out. Forgot you will need to remove o2 sensors first if you haven't already.If you don't like that just try chiseling off the jb weld? It's very fixable from the sounds of it, just gonna take more steps than usual. Good luck.

 

Haha I hate when people are so half ***, especially about their vehicles. Atleast we can eliminate a novice flash from the list of possible problems. I'm no turbo expert or anything but I would look for leaks/collapsed lines around the turbo. Could be your lines collapsed under the pressure of higher boost and this is limiting your boost from rising. Especially if its an intermittent problem where the car will run up to 15 pounds of boost and then drop off. Just an idea, like I said, not an expert.

 

Turbo Intake Pipe Collapse?

This might help you out, this guy seemed to be having similar problems. Its a lot to read, page 3 he determines his problem was a bad N75 Valve.

 

so im 99% done removing my stock turbo and i cant seem to get the main oil line off the turbo. i got the 19mm banjo bolt off, but is there a bracket i cant see? i took out a few alan head screws along with the ones that were jb welded to the down pipe SMH. i got the 3 off that are up on top that bolt it to the exhaust manifold... does anyone have pics of a step by step turbo removal? and back to the original question KDaviou last asked, ive been looking for the best n75 valve but i get 2 that pop up for my car and im not sure which one to get. theres a "J" and an "E" which one?