Closed lope runs very lean open fine

[1996chevyys10]

Here the run down on my project is a 03 4.3l ported polished heads, .516 lift cam 10.5:1 compression headers, marine intake, with 33lb injectors off of a 06 corevett so I used the corvette tune for the injector set up. But to get on with what I'm getting at. I started off tuning the VE table with a wideband got it spot on all across the board up to 3000 rpm. Then I went to tune maf with the wide band again got it spot on 14.1 threw rpm up to 3k. So I went ahead and turned on ltft and stft and closed lope. And the trucks narrow bands stay rich and then long term and short tearm just keep taking away fuel till about 20:1 afr then the narrow o2s start to bounce like normal Replaced o2s again same story goes lean but runs great in open lope. Smoked the intake no leaks I even smoked my exhaust still no leaks. Short tube headers. O2s about 6ins away from collector. I haven't tested heaters but key on engine off narrow bands read lean so heater is working unplug pcm says 450mv. Could it be my maf is not diled in right. All help I appreciate in advance.

[chevy 6.0]

How does it run at 20-1 ? Whats the lobe separation on that cam ?

[Dr. Nopps]

Triple check your injector data. You might not be able to just enter the Corvette info. You may have to do some math between the two sets to get the right numbers. If the injector data is even slightly off you will have a nightmare starting literally at square one, and it will keep growing exponentially from there.

[1996chevyys10]

I figured it out my o2s are isolated ground not case ground For what ever reason the pcm needed 4 low references pin c2 63 29 28 26 tied together or into a splice pack now and then I branched it off into two wires into the 02s and long story short I though I wouldn't have this problem but happens when you take a 96 and do a 411 pcm swap and though it was a 03 computer turns out to be 2002 witch is external splice pack where 03 from what I understand is internal on the computer idk I'm glad I got it working now I'm happy Does great with stft on and ltft disabled that's all I wanted thanks for the help though guys!