Photochop

iTrader: (74)

Last night I changed the plugs on the car and noticed that every plug on the drivers side looked fine, lil gray, nothing bad...and every one on the passengers side was fuel fouled. Is this a sign of a bad 02 sensor even though the computer hasnt thrown a code yet? I also thought maybe a leak in the intake, but I haven't noticed it not making or losing boost. The turbo is on that side of the motor (hiflo kit) so I thought maybe running thru the catback was richening up that side somehow more than the other? (running thru an open cutout lately, but had it closed for a while). Didn't think that was as likely, but figured I'd mention it. Any suggestions would be appreciated before I go and spend $100 on a new 02 sensor...

kp

iTrader: (34)

Its possible, you can also have an exhaust or vacuum leak affecting the O2 on that side.

Logging software can be your friend

Photochop

iTrader: (74)

Yeah, well just got it back from the tuner last week and he told me he doesnt keep the logs. I guess it was logged during the tuning session and didnt show up anything then...so, it had to have happened in the last couple times ive driven it (havent put much street miles on it since I got it back - maybe 75mi). He also said he had the 02s turned off during the WOT tuning? He did a 2 bar SD tune, not sure why he turned them off exactly. Maybe 'turning them back on' caused an issue?
Wouldnt an exhaust or vacuum leak show up on the vac/boost gauge? Lower vac reading at idle or less boost because of an exhaust leak? Both of these are the same. Really thinking its the 02 sensor. I'm debating swapping out the 02 on that side for a new one...but may switch the sides of the 02s and see if that causes the drivers side plugs to foul instead. You think I'd be able to get any money back out of a 'mildly used' 02 sensor if that doesn't fix the problem?

kp

iTrader: (34)

Just swap them around, but without some kind of logging software you really wont know whats going on. An exhaust or vacuum leak wont really show up on a gauge unless its massive, doesnt take much to mess with the narrowband sensors..

They may have turned the O2s off if its a an open loop SD tune, if thats the case then you have other issues..

Photochop

iTrader: (74)

The 02s are on currently. I think he just turned them off for the WOT tuning.

I also found out they're bosch sensors, which I've heard from a couple folks can give not so accurate readings and frequently call for the wrong amount of fuel for driveability. I've noticed it doing some odd things lately, I may go ahead and swap that sucker out...

01SOMm6

iTrader: (4)

Ive been having this same Problem but its with a S/C. I still havent figured out what it was. Havent had time to get it retuned or checked yet. Went through 3 sets of TR6s (.032) in a week and a half.
I will have to check my 02s and see what they are.

Photochop

iTrader: (74)

OK, update.
I popped the hood last night and double checked the location of the o2 sensors before I got to swapping their locations. On this turbo kit, the drivers side (bank 1) o2 sensor is located at the end of the header right before the crossover. The other o2 sensor (bank 2 - normally the passengers side) is located on the crossover pipe BEFORE it even reaches the merge before the turbo - NOT inline of the passengers side header. So really, the information that o2 sensor is receiving is from the same bank - bank 1.

So, since I was using my parents garage for this little project (yeah yeah, savin up for a house and currently the only easy accessible wrenching spot haha), I was forced to relocate the car. I fired it up, took it around the block and toggled thru the parameters on the aeroforce interceptor scan gauge. I set both visible parameters to the 'o2 millivolt' option. Funny thing was, bank 1 - the o2 sensor that is on the drivers side header collector was the one that was bouncing from 100-700, making adjustments I assume. The other bank o2 sensor was steady at 380. So, I'm guessing since it was stationary and flat at 380 then it wasnt make corrections. So, I guess its safe to say that was why it was the side with the fuel fouled plugs (bank 2 - passengers side).

So, I plan on replacing the passengers side o2 sensor tonight, and I'll report back.

mike13

iTrader: (27)

Strange that you haven't thrown a code, there is a couple of codes specific to the O2 sensors like O2 insufficient switching.

Photochop

iTrader: (74)

Well I changed out the passenger side o2, and the problem still exists. Not sure what the heck is wrong with this thing. I'm going by the shop that tuned it and having them switch it to an open loop SD tune and I'm going to try driving it like that - thats all he has time for today. The tuner said he never experienced what its doing when he had it, but he was doing the WOT tuning in open loop not closed for those pulls. If it still sucks in open loop I'm taking it back and letting him sort it out. This is getting to be over my head I'm afraid as I don't have my own scanner, etc.

Photochop

iTrader: (74)

OLSD for the win! Put the car in open loop and no more issues.