Brett H

iTrader: (2)

I did some logging over the weekend to try and find out why I was down on power and one thing that I noticed was that my bank 2 narrowband reading were as much as 950mv for the entire run while the bank 1 reading averaged between 890 and 919mv.
Could this simply be a failing O2? I know I am running fat because of the black smoke on passes so it is definitly rich but I am unclear why and why only 1 bank. Can someone please give me some input as to how I can go about figuring this out.
Also is it possible to pull fuel from only the pass. side in HP Tuners? I went through the tables but I'm not versed enough with it yet to know how or if I can do this.
What else can cause 1 side to go fat, could it even be just 1 cylinder? Any help is apprectiated.

Boodyrider

iTrader: (2)

There is no way on earth the narrowband is accurate enough in that part of the range to determine ANYTHING from those readings.

Possibilities:
It really is richer on that side
The O2 on one side or the other is lazy or dirtier
The ground on one side or another has a TINY bit more resistance.


You'll need to use a wideband for valid data.

PREDATOR-Z

Check O2s

txhorns281

iTrader: (12)

in addition:

Possible exhaust reading contamination from a small leak intake/exhaust would make a bank look leaner than another (meaning that you're actually running rich altogether)

Definitely can't rely on O2s to substantiate anything conculsive. And no, the factory controller does not allow for specific bank adjustment

Brett H

iTrader: (2)

Thanks for the input. I know the narrowbands are not good for **** but I thought it was an indicator that something was wrong.
I'll clean all my O2's and check bank1 for exhaust leaks then I guess its off to a tuner because I don't want to continue to run the car like this.

RedHardSupra

iTrader: (1)

they are an indicator, albeit a very vague one i had a similar situation, i swapped them left to right and saw the 'condition' follow the swap, so I put in new O2s and the problem was gone. swap it, see what happens

Brett H

iTrader: (2)

So which O2 would be the problem? The front or rear and which side is correct?

Maybe I will try and clean them with brake clean first, if it doesn't change I'll swap sides and log to see what happens.

RedHardSupra

iTrader: (1)

fronts, rears are more of a 'second opinion' sensor

slow

iTrader: (7)

Fronts are used for CLOSED LOOP fueling only, and only keep the motor at stoich for the fuel your running, typically 14.6x for gasoline.

The rear's are just to tell if the CATS are working or not.

Both are garbage for telling you about your airfuel ratio at WOT. And can only be used to tell if you are rich or lean.
That's it. <-- yes, that's a period.

Ryan

under_construction

iTrader: (1)

Replace /check all spark plugs and wires. I had a bad plug wire, leaving one dead cyclinder - that bank would read rich, and the car would pop and backfire more. Found it by pulling injector connectors at idle - the cylinder that does not dip the idle speed, is probably your dead one.

It was also almost 100 rwhp down on the dyno too, but idled and ran pretty much fine.