1998 Z28 that was swapped over to an 0411 pcm (harness repinned) and the motor was swapped from the og 5.7 to a 6.0.

I've had the car running in open loop ever since because the o2s are essentially doing the exact opposite of each other. Under moderate acceleration bank 1 pulls a -40 or so fuel trim and bank 2 adds 30+.

As you can imagine the car runs like pure **** while running on the o2s.

I've tried 4 different sensors in each header with no difference at all.

I've tested for continuity for each O2 sensor several plug as well at the PCM pins and they check out and are where they are supposed to be.



I'm lost. What a pain in the ***...

 

If the 02 ltft are very much opposite, I would verify they are not swapped drivers to passenger side.

 

The stft are almost total opposite and when attempting to drive the car with them active, it runs like total ****.

I know they aren't swapped, because when i unplug bank 1, then bank 1 reads ~450 at the pcm

 

ok can you post your tune ?

 

Yes, I will get a copy.

 

good thought, can you change the side they are assigned to? I would almost bet if you swapped them it would work. I’m going to look at me o2 settings.

 

Don't know if they can be swapped inside the tune... but I confirmed for the FOURTH time tonight that the harness is pinned properly.

 

All I see is injector bank select. Injector A is set to bank 0. Injector pos could be swapped too.

 

how hard would it be to repin them backwards and see what happens. It would fit the symptoms perfectly and I don’t have enough Ls experience to imagine what else it could be.

https://ls1tech.com/forums/pcm-diagnostics-tuning/1905077-how-tell-if-left-right-o2-sensors-wired-backwards.html

 

I dont have the correct tools for pinning, but I do have extra long o2 sensors that will reach opposite sides. I may try it but I cannot get over the fact that I've ohmed out the pins on the connectors and pcm and verified it all 4 times.

 

Bump.

I haven't tried swapping the pins and the sensors won't reach. I have not obtained a copy of the tune yet but should see it within a couple days.

Tonight I went through the entire MRK Motorsports writeup and confirmed that every single wire *appears* to be correct. The colors match where they should. I have already ohmed out the o2 sensors to confirm they are pinned in the correct spots.


Still lost!!!

 

It sounds like u have it pinned correctly. It could be the injectors assigned to wrong side would have same effect. Or if u get a Ferrari w/2 MAF swapp them and it would do this.

 

Here is the tune file (I can't look at it) so hopefully someone can see something.

 

Dude what in the hell is going on with that file, none of that matches what I would expect to see with your combo listed in the signature and the bank select as well as the firing order is all dicked.

 

Well for one, those are no longer my mods. The car is a 6.0 LQ9 swap at 12psi Procharged. Deka 60s. 340 pump etc ect etc.

Can you elaborate on bank select and firing order? What do they show and what should they show?

 

Ahh, OK.

They are totally wrong and could definitely cause the issues you are having. Who did the tune on this?

This is what it should be, this is just a stock f-body file.



This is the file you posted up.

 

Sorry For the confusion haha. So it's a long story but RPM Speed/WS6 Store tuned it first and it was a complete disaster. The VE tables were a joke, they used the wrong injector data and so on. Terrible .

A smaller new shop tuned it after and maybe he overlooked this part. He probably didnt look at and just started fixing the other, more severe problems. What I can say, is that he crushed the tune and helped me fix a ton of prior mistakes. Including a bunch of problems with the 0411 swap because rpm speed/ws6 store is Incompetent.

 

I just spoke to my new tuner and he did confirm that we've never touched or switched any of that. Go figure, another lingering rpm speed problem.

 

I'm wondering if they thought it was an LT1 swap setup? Looking at the injector bank select table it mirrors what I would change it to for an LT1 with an LS1 computer but the firing order table still seems screwed.

 

So you believe that adjusting the tables you showed me above will take care of it? Anything else you've seeing? Car made 560hp and it runs really great.