I have just installed a 3" turboback exhaust (HKS downpipe with a Tannabe hyper medallion cat-back) and a solid uppipe. Other mods only include the silencer being removed.

My turbo now takes untill 4k RPM's to spool completely, I have stock boost levels with no sort of boost controller and only a boost gauge that reads peak boost at 9-10 pounds.

I checked for uppipe leaks, downpipe leaks, melted vaccume lines, disconnected vaccume lines, nothing seems to be wrong... I do have a CEL for the oxygen sensor and I ordered the fix for it.

I have talked to a few people and still cant seem to figure out what is really wrong. I am thinking I should have just gone for 2.5" exhaust instead of 3"? I plan on getting the COBB stage 2 reflash asap and hope this helps out.

Anyone else have this problem or know of what i can check next, its driving me crazy that my car is being so slow and want to diagnose the problem asap.

 

Thanks for the reply, I tried resetting the ECU once... I disconnected the negative terminal for abotu an hour, then started the car up, let it come to operating temp, shtu it off, then turned it back on and drove it hard (took it to redline in 1st and 2nd)

My CEL was still on though and I dont know if I resetted it right, I have seen so many ways to reset the ECU and just tried something I thought would work....is there a diff. way I shoulda tried to reset it??

 

Anymore idea's?? Resetting the ECU dosent seem to be working

 

Which sensor is giving you a CEL? EGT or O2? Have you done the 2.2KOhm fix for the EGT? (Either way, an EGT cell should not affect performance). I'd make sure you get rid of CELs before trying to fix the appearant issue. Remove all the known variables first. What this O2 sensor fix you ordered? web page link?

As for overboosting, my car never went into limp mode after overboosting when I had an MBC. Heck, I've been in WRXs with very audible detonation that did not go into limp mode. Generally misfiring will cause that, not over overboosting.

What do you mean by "spools completely". Under normal conditions you most likely won't see full boost until 4000RPM. Spooling up is when boost comes on, that is when the turbo gets intake pressure above atmosphere. If you mean you are seeing the boost meter cross 0 PSI at 4000RPM, then you've got some problems.

Where are you seeing this 9 or 10 PSI? If its way late in the RPM range that sounds OK too since boost is supposed to taper as RPM get to the end of its range. As long as you're peaking between 4000 and 5000rpm at around 14PSI or more, you're doing fine.

jason

 

by "spools completely" I mean to say at peak boost, and my boost gauge only reads 9-10 pounds max at 4k-5k rpm's, it has always read that much stock and still does after the mods and never more since the day I installed it. It is an OBX gauge, I talked more to the guys at Cobb and they think I might need a better boost gauge....

Anyway, when I reset the ecu I hit the brake pedal a few times for a few seconds at a time...

I just got the 02 CEL fix (the resistor method)

 

You might have an exhaust or charge leak. With the exhaust mods you have done, your turbo should spool much better than stock.

 

how weird, i just installed a helix downpipe, with everything eles stock and just a straight pipe axleback and my car doesnt really seem to haul untill 4k or higher. I would think that my turbo would kick in alot faster... Im bummed out, I receted my ecu while i did the cel fix for the downpipe sensor. The car seems to rev up as if its N/a its either the turbo kicks in so fast that i cant notice lag or its aleak, My oem boost gauge seems to be working the same though. I even bolted on the Oem muffler and that didnt help either. I remember before the helix downpipe, once the turbo kicked in the rpms picked up alot faster. On the flip side though i have alot more power in low end power in 2nd, i can take off in 2nd and the car wont shake... Odd. Any help i would appreciate it.

 

some updates: I found a leak where my DP connects to the rest of my exhaust, the gasket is ordered to fix that....AND I finally felt some small bursts of air coming out around the uppipe the 45th time I checked, haha. So I guess I need better gaskets and my problem should go away??

COBB stage 2 ECU is coming soon too...