Sluggish/Sputtering 02 WRX (P0030, P0171)

[L0athe]

For a couple months now my bugeye seems to have lost all power. At about 3500 to 4000 rpm when the car should really start to pull it feels like a fuel cut of some sort and the car bogs terribly. The idle is also bad and drops as low as 500rpm.

It's throwing two CELs:
P0030- Front O2 Sensor Heater Control Circuit
P0171 - System too Lean

Modifications on car:
HKS Carbon TI Cat back Exhaust
4" Cattless Downpipe (Not sure of brand)
Perrin Cattless Up Pipe
Blitz BOV

I just installed the UP last weekend thinking maybe my pre-cat was falling apart and causing the sensor to foul. The Perrin UP has no bung for the sensor (a/f?) so I bought a 2.2k ohm resistor and plugged it into the female end of the socket and taped it off. After this I went to Autozone and cleared my CELs, which came right back on driving home that night. I have not been back to see if they are the same codes, I well check this weekend when I have some time.
I've heard nothing good about aftermarket BOVs at this stage of mods so I will be replacing with the stock one this weekend.
Also I've heard that cleaning the MAF can have a big impact. I will also be doing this. I have removed the portion of intake that sits inside the passenger side fender (the snorkus i believe), could this be causing it to lean out?
I drive the car regularly to work every day, and has no real problems when driving conservatively (shifting at about 3500), but trying to pick it up any more than that and I get cut almost exactly at 4000rpm.

Is there anything I've missed that could potentially be causing these codes? I'm reluctant to go down to the Subi dealer and spend 200$ on a new sensor but will if I have to. Would changing the plugs make any difference at this point? Could it be a bad fuel pump? Fuel pressure regulator? Injectors? Any additional ides would be greatly appreciated, this has been driving me crazy for some time now and it's to the point that I've forgotten how much fun these cars can be to drive.

[wrxisthebest]

ok.... lean with a BOV??? thats wierd... and i would suggest gettin a UP with a bung instead of using a resistor.. i know the resistor way works, but it can also cause the lean and the heater circuit... just the other day(im in high school) we had to clear codes of an OBDII vehicle so we used a 2001 honda civic, when we disconnected the O2 sensor the same codes popped up, so i would recommend getting the helix flex up pipe, i have one, and i have no codes popping up



P.S.- Auto zone will clear codes for me, i am going to be installing a dp and i need to get the CEL cleared, will they do it?

[wrxisthebest]

oh, BTW take the BOV off and see if it helps with the idle issue, some BOV's sometimes cause bad idles, so just istall the stock BPV and see if it helps at all!

[alewis814]

For a couple months now my bugeye seems to have lost all power. At about 3500 to 4000 rpm when the car should really start to pull it feels like a fuel cut of some sort and the car bogs terribly. The idle is also bad and drops as low as 500rpm.

It's throwing two CELs:
P0030- Front O2 Sensor Heater Control Circuit
P0171 - System too Lean

Modifications on car:
HKS Carbon TI Cat back Exhaust
4" Cattless Downpipe (Not sure of brand)
Perrin Cattless Up Pipe
Blitz BOV

I just installed the UP last weekend thinking maybe my pre-cat was falling apart and causing the sensor to foul. The Perrin UP has no bung for the sensor (a/f?) so I bought a 2.2k ohm resistor and plugged it into the female end of the socket and taped it off. After this I went to Autozone and cleared my CELs, which came right back on driving home that night. I have not been back to see if they are the same codes, I well check this weekend when I have some time.
I've heard nothing good about aftermarket BOVs at this stage of mods so I will be replacing with the stock one this weekend.
Also I've heard that cleaning the MAF can have a big impact. I will also be doing this. I have removed the portion of intake that sits inside the passenger side fender (the snorkus i believe), could this be causing it to lean out?
I drive the car regularly to work every day, and has no real problems when driving conservatively (shifting at about 3500), but trying to pick it up any more than that and I get cut almost exactly at 4000rpm.

Is there anything I've missed that could potentially be causing these codes? I'm reluctant to go down to the Subi dealer and spend 200$ on a new sensor but will if I have to. Would changing the plugs make any difference at this point? Could it be a bad fuel pump? Fuel pressure regulator? Injectors? Any additional ides would be greatly appreciated, this has been driving me crazy for some time now and it's to the point that I've forgotten how much fun these cars can be to drive.

the bov is causing the such low rpms, ditch it and go back to stock. bov's are not required untill stage 3, as for the bogging you could probably have faulty spark plugs causing it only to fire 1/2 or it could deffinetly be your fuel pump

[ZACK777]

got the same problem as you man ive replaced the plugs and coils and still not running perfect im doing the fuel system this weekend new pump filter injectors and rails hopefully that helps

although i never threw any codes thats the only difference -weird-
good luck