SS3520

what would cause O2s to be much lower in one bank rather than the other. I am getting .91 on one side and about .6 on the other. Engine sounds fine and feels strong. Could this be a bad o2 sensor, or possibly an exhaust leak? Anyone seen anything like this before?

jimmyblue

iTrader: (11)

That's a fairly large imbalance. A bad sensor might do that
but at WOT it should be hot and working. Check the
downstream sensor (if it's still there) and see if it
corroborates the story.

Side-side gross imbalance might come from a problem in
the "bridge" tube / pulse damper. Could also come from
one injector being "lazy" / crudded up and losing flow.
I would expect that kind of O2 reading (if true) to be
giving you strong KR.

Texas Terminator

OUCH! that is way off! sounds like you are on the right track though. try what jimmyblue said too. how long has it been doing this? did you change anything?

SS3520

This is the first I have seen it, but I havn't loged a WOT run in a while. Here is what I logged. As yuo can see, no knock... Which is why I was thinking a bad sensor or leak. I have sims on the back, so no help there.

Engine Speed Knock Retard O2 Sensor - B1S1 O2 Sensor - B1S2 Ignition Timing Adv

2928 1.5 0.905 0.435 26.5
6241 1.4 0.925 0.435 26
4700 0.4 0.93 0.435 22.5
4534 0.3 0.93 0.44 23
4785 0.2 0.935 0.835 22.5
5002 0 0.92 0.835 24.5
5293 0 0.93 0.83 26.5

1349 0 0.035 0.435 18.5
4615 0 0.92 0.44 23
4890 0 0.935 0.435 23.5
5148 0 0.935 0.435 25.5
5525 0 0.93 0.435 27.5
5870 0 0.94 0.83 27.5
6210 0 0.935 0.825 27.5
6474 0 0.935 0.83 27.5

Doc99SS

iTrader: (2)

I would recommend that you swap the O2 sensors from side to side and see what happens.

Bad30th

iTrader: (13)

Also keep in mind that exhaust leaks can wreak havoc on your O2 readings. Make sure the "lean" side (.6) doesn't have any air leaking in before the O2.

Good luck,
Bad30th

SS3520

Thanks for the replies. The more I think about it, the more I think it might be a bad sensor. I will try switching it. I have not removed the exhaust, so I don't think thats the problem and I know I have had normal reading since the last time I removed it.

John02SS

iTrader: (47)

You are autotapping the wrong one. You are doing the drivers side front and back. You need to be looking at B1S1 and B2S1. That should take care of your concern.

John

Doc99SS

iTrader: (2)

John02SS is correct, you should be logging only the front O2s, B1S1 and B2S1.

Thats Bank1 (drivers side) S1=front position
Bank 2 (pass side) again S1=front position

SS3520

Yea, tried that and all is well now. Thanks.

WS6FirebirdTA00

iTrader: (33)

haha, dont you love the easy fixes

1ORANGEWS6

Could you have an exhaust leak and not hear it? I had the pass. side cat replaced after I got a SES code. I have the same problem except mine is 4.5 on side and .08 on the other and I got KR. I can't hear an exhaust leak and I couldn't see any suet around any connections/joints and the all the nuts were tight. I pulled off the O2s and was going to swap them but the pass. side is shorter than the drivers side. Will this cause any damageif not corrected? Would this also cause shitty gas milage?

WS6FirebirdTA00

iTrader: (33)

waht are your o2 numbers? make sure they are both the fronts. why did u replace the cat? if your banks are that far off i would start with plugs and wires cuase my guess woudl be its not burning all the gas and could have made your cat get bad. jsut a thought

1ORANGEWS6

They replaced the cat because the dealer said it was inefficient and was throwing a code. I haven been getting a code after that but my mpg is pretty bad. As far as reading the front or rear O2 or what their number were reading I couldn't tell you a buddy of mine was autotapping the car and he has that info. On the plugs and wires I changed the plugs out with some TR6s and the wires looked pretty good so I didn't change them. Where would you look for a vac leak. I here a what sounds like a leak but I can't tell where its coming from. Is there any kind of test I can do to find the source.