my 02 wrx has an odd bouncing boost( best way i can think to describe it.) when you get on it heavy into boost it will go right to full boost around 12 then cut back down to around 7 and will bounce up and down like that 5 or 6 times before leveling out around 12 again? it also idles rough i idles between 500 and 1500 rpm reving up and then almost cutting out and catching itself and then reving up again , when you watch the boost gauge it looks like the vacuum levels change before the idle does. cel on but just for the dp o2 sensor. and only mods are headers and three inch cat-less exhaust. what could be causing this?
02 wrx bouncing boost levels?
- Thread starter kblood477
- Start date
dsmith
Active member
the idling could be an o2 sensor. My car idles like that because I have no current going to the o2 sensor on the header.
drvsdwz
DRiVe SiDeWayZ
only the header o2 will cause that, the dp one is only for cat inefficiency.
My guess is that you could have a boost leak. Any way of checking what your idle afr is(i.e accessport)?
My guess is that you could have a boost leak. Any way of checking what your idle afr is(i.e accessport)?
drvsdwz
DRiVe SiDeWayZ
HR radness
His royal radness
Look for any vacuum hoses that may be loose/not connected
Meyagi
I'm a hack
make sure the restrictor pill is in place in the wastegate line
drvsdwz
DRiVe SiDeWayZ
has the car been tuned for the headers and exhaust? what kind of headers? equal length or unequal?
no the car has not been tuned they are unequal length. and there is a possibility that i have a small leak on the headers right before the o2 sensor, do you think that could cause it all? what is the restrictor pill?
i will check my afr also . i think the program i have will check that
i will check my afr also . i think the program i have will check that
drvsdwz
DRiVe SiDeWayZ
You need a tune. Your afr will be way off because of your way less restrictive exhaust system. Do that and see if you're still having issues
OVRBST
Vendor
The idle may be the notorious Idle Air Control valve. It's a $270'ish part from Subaru. They fail frequently and will cause all kinds of idle issues. A tune will help clean up the wide open throttle stuff and the fluctuating boost you're seeing. Before buying anything though, I highly suggest doing a boost leak test to eliminate any vacuum/boost leaks which is the other major cause for erratic idle and irregular boost.
Shoot me an email if you need specifics on what to check/look for/buy.
[email protected]
Shoot me an email if you need specifics on what to check/look for/buy.
[email protected]