O2 sensors don't work after 0411 swap L31 Vortec

MrOverCast said:

The 0411injector data was set for 3.00 grams/sec for the 24 lb/hr injectors using tuner pro. Injectors are running at 60 psi constantly. And I never tried that. I assume it wouldn't care but I could give it a try.

Click to expand...

I don't know what you know, so bear with me here. Are those 24# injectors 24# at 60#? I believe many are rated at 43.5#. Did you use Tunerpro to make it a 5.7 tune as well?

Supercharged111 said:

I don't know what you know, so bear with me here. Are those 24# injectors 24# at 60#? I believe many are rated at 43.5#. Did you use Tunerpro to make it a 5.7 tune as well?

Click to expand...

I used tuner pro to change the injector data and remove vats...

Runs bad when cold, but after reaching temperature runs good ? So after reaching temp do have feedback from the O2 sensors.? The number 1 sensor on each side is providing a/ f ratio mix signal so what's going on that's diff' when warmed up?

GoToGuy said:

Runs bad when cold, but after reaching temperature runs good ? So after reaching temp do have feedback from the O2 sensors.? The number 1 sensor on each side is providing a/ f ratio mix signal so what's going on that's diff' when warmed up?

Click to expand...

Barely starts when cold. Plugs are wet when checked. As the engine warms up it gets slightly better. When it's fully warmed up I still get no o2 movement. The point of this post is there's absolutely no movement at all. Hot warm cold etc nothing

Is it my imagination, or are you running injectors rated for 43#, at 60# of constant pressure? And could that be contributing to a compound problem (i.e. two or more issues that haven't been distinguished and/or separated and fixed)??

Was there ever a solution to this problem? Seems like these kinda things rarely have a posted solution...

210Tumbleweed said:

Was there ever a solution to this problem? Seems like these kinda things rarely have a posted solution...

Click to expand...

Sorry it's been a while and I didn't think anyone really kept an eye on this post. Anyways, I found out what the problem was a month later. apparently some 0411's from different years have their O2 sensors wired internally differently. And there are two types of O2 sensors, Case ground sensors and Isolated ground sensors. So the stock sensors that are on the 95 through 2000 that are Isolated ground. And they changed to case ground in the 2000s.

Something
like that it's not 100% accurate but basically as far as I know I had Isolated ground sensors with PCM that's designed for case ground sensors.

I don't know maybe I bought the wrong sensors when I first encounter this problem? I bought the stock post cat O2 sensors

So in the end I had to buy NTK 24626 which is apparently case ground, so this solved all my problems by buying those NTK sensors and now the ecu is reading the trims normally

So for those of you googlers or post surfers seeing this. If you run into this issue after doing an 0411 swap you might want to look into what type if sensors you have on your vehicle you're 0411 swapping and what year vehicle the 0411 came off of and what type sensor that vehicle had

So if I understand correctly, I just did the 411 swap into my K3500 with a 7.4( actually a 461 now) and it will fire up but pops and runs HORRIBLE. Tried numerous tune parameters from a 2002 Express 5.7 BIN. I have headers with no rear O2 sensors and the upstream O2s that came stock in 99'. Possibly the problem? Should get O2s from a 2002?

An engine will still run well without 02 sensors at all. Pops and bangs sound like a mechanical issue. Firing order, lifter pre-load, distributor timing, etc.

Jedc said:

So if I understand correctly, I just did the 411 swap into my K3500 with a 7.4( actually a 461 now) and it will fire up but pops and runs HORRIBLE. Tried numerous tune parameters from a 2002 Express 5.7 BIN. I have headers with no rear O2 sensors and the upstream O2s that came stock in 99'. Possibly the problem? Should get O2s from a 2002?

Click to expand...

Are you sure that isn't a tune related problem? Does it idle fine? Also if the O2 sensors aren't working you would see them be flatlined at 450mv