Weird O2, ECM Operation Problem

[GHuggins]

Just realized I put this in the wrong category.

I've got an interresting one that I'm just not quite sure on. Basically Bank 1's 02 sensor is controlling all of my short and long term fueling for both banks, atleast that's what I can tell from the datalogs. This would initially lead one to believe that bank 2's 02 is bad or has a poor connection or atleast something to that degree, but it's been replaced once for this already and nothing has an effect on it. Bank 2's 02 works fine. Fueling on a wideband is almost spot on bank to bank with throttle, but at idle, since bank 1 is running a touch richer the ecm leans out bank 2 to the point where the 02 just stays at 80 to 90 or so mv's. Fueling seems rather sensitive on this thing. I'm currently working on my VE SD patch, so don't be surprised to see it a little off in the datalogs.

I think this all began along the same time headers were installed and the cats were gutted. There are no leaks on bank 2's exhaust system. I was wondering if something could have been done in the tune that would cause this (basically having to change the precat O2 dtc's due to the headers), but I'm not seeing anything wrong. Of course it wouldn't be the first time I've stared at something and couldn't see the forest for the trees... The headers are also ceramic coated, which I know goes even further to keeping the 02's from getting "heat" and switching correctly, but still this isn't the problem. My problem is bank 1 is controlling all of my fueling which is causing bank 2 to go lean.

Vehicle is a 2013 ZL1 camaro. The one in my signature... Working on tuning in the cam before the motors pulled and stroked. Tune is a little off from being done - obviously... Any info or help will be greatly appreciated. Just wondering if anyone else out there has had this problem. You will see the problem I'm talking about toward the end of the SD tuning datalog at idle then of course the fuel trim issue all throughout the datalog. After doing my "road verification", I did find bank 2's fuel trims starting to read a little different, but still no compensation at idle.

[Road]

Bank 1 and 2 are staying below 450 mv too long at idle. The only I see or would suggest is increase bank 1&2 R/L vs airflow to @450-500mv. Also that is one nice shop you have.

[Dr. Nopps]

Have you tried swapping the sensors themselves between banks? Also if wiring length permits, could you actually swap the bank 1 and bank 2 circuits with each other to see what happens?

[GHuggins]

Bank 1 and 2 are staying below 450 mv too long at idle. The only I see or would suggest is increase bank 1&2 R/L vs airflow to @450-500mv. Also that is one nice shop you have.

Yes this is probably the nicest shop I've ever worked in. Thanks for the comment. As for the O2, when I read that, I thought for sure I had already changed this. BUT atlas, I hadn't. However it didn't fix the problem Thank You for the suggestion.

As for O2's. I have already switched banks and even tried replacing the O2. Nothing worked. I'm really thinking that this is heater circuit or heater control circuit related. I noticed on my last scan heater dtcs were never being tested even though they aren't off in my dtc list - atleast not the precats. Wondering if the ecm is seeing something here and resorting to the one O2 for fueling at idle and the majority of the rest of the time. I have read where some out there aparently are hardwiring the O2's to ground to fix the issue then turning off the dtcs, so their taking the pulse width modulation of the O2 heater circuits out of the equation.

Don't know, have to get back to tuning.

[ingsteve]

can you increase the flight time? maybe the headers have something to do with it and the correction is late

[GHuggins]

can you increase the flight time? maybe the headers have something to do with it and the correction is late

I don't know how to do this other than increasing open loop time. I know on Fords they have have a time or temperature from exhaust valve to O2 that you can change that does just that. Haven't seen anything like that on this one. Hard to accept just how many more parameters a Ford has to program vs a GM product or just how much more tuner friendly they are. Probably going to get some hatrid for that remark, but it's true

OR maybe it's just my stupidity... Is there a way to adjust this?

[ingsteve]

It should be Closed Loop Integrator Delay "Airflow" but i'm not 100% sure.
You might try to increase at 20% steps the whole table.
I assume you have long tube headers installed and therefore you have increased the distance from of the O2 placement to the engine.

[yonson]

You might get more response in the Gen 4 section...

[GHuggins]

You might get more response in the Gen 4 section...

But this is a 5th gen car??? Anyway it's there too.

Haven't tried changing the o2 airflow yet. Did not dawn on me that this was for the temp difference with long tubes adjustment.

[ingsteve]

it is the reaction time the problem and not the temp...

[Road]

Lack of back pressure? Put the cats back on if you want the o2 sensors to work right the install some dumps for those times you don't want the work

[yonson]

But this is a 5th gen car??? Anyway it's there too.

Haven't tried changing the o2 airflow yet. Did not dawn on me that this was for the temp difference with long tubes adjustment.

This forum is for 5th Gen. LT1 engines, not 5th Gen Camaro's...

[GHuggins]

This forum is for 5th Gen. LT1 engines, not 5th Gen Camaro's...

Ahhh yes, guess I should have read the header under the 5th gen forum title...

Well to all those who actually or atleast tried to help. Thank you very much.