I've been working on my swap for a couple of years now, Finally got it fired up and after chasing down a few issues like various vacuum leaks and O2 sensors not working I'm struggling to figure out what's going on with my STFT. I'm trying to figure out if this is a tune issue or if I need to look at something else mechanical or sensor related. I did a mail order tune to get going, and provided all my mods/injector info, etc.

Initially here are the readings I got at idle when the car went into closed loop:
STFT Bank 1 = 26.6
STFT Bank 2 = 26.6
O2 Bank 1 = .030
O2 Bank 2 = .045
MAF = 1.30 lb/min at idle
MAP = 18 (inHg)

I contacted my tuner and got a revision. When I fired it after with the new tune, the STFT for both banks were floating around -3/-5. But, the O2 sensors were reading between 700/800mv.
Then it went into closed loop and did the same thing - STFT went to 26.6 and the O2 readings went lean to .010/.040. It also idled rough and with a little throttle it would bog and stall instead of coming back down to idle.

So I unplugged the MAF to see what happened and got these readings in open loop:
STFT Bank 1 = -12.5
STFT Bank 2 = -14.8
O2 Bank 1 = .795
O2 Bank 2 = .795
MAF = n/a
MAP = 17 (inHg)

Then it went into closed loop and the readings stayed about the same. The motor still would stall with a little throttle and letting off (wouldn't come back down to idle).
After 5 minutes or so, the idle started getting better and it would come back down. Thought I was home-free (meaning I figure out it was the MAF readings).
Then, the STFT started creeping up and went back to 26.6, and both O2 banks went to .030/.040. So basically back to where I started.

Here are the mods:
LM7 from a 2006 Silverado - cam and long tube headers
4l60e from the same donor truck
Blue/Green PCM from the same truck - tuned by mailorder tuner to remove VATS, tune for the engine mods
PSI Conversion harness (HAR-1014)
the PSI C10 swap pedal ((ACC-1049) with pedal harness (HAR-1022)
New TAC purchased from PSI when I got the pedal
Corvette style filter/regulator - new with swap
255lph fuel pump - new with swap
New DW injectors

I've smoke-tested for leaks and confirmed no vacuum leaks.
Injectors aren't leaking and are all firing (I did the stethoscope thing). Fuel pressure is a solid 58psi at idle and part throttle.
New PCV, new MAF, all new vacuum lines, new coils (all 8). I don't hear and exhaust leaks and have tightened all the connections near the header/collector.

Really struggling here to figure out a couple of things:
1. Does this sound like a tune issue or something else?
2. Would this be safe to drive around the neighborhood to data log or drive to a tuner?

Any help is appreciated.

 

You would need to post a tune and log.

 

I'm new to HP Tuners so I'm still trying to figure out to pull the tune (I had it tuned by mail to get the motor started). Here's my log of the car idling. I didn't give it any throttle until the end where I held it around 1500 for a bit. Would you need to see the tune to know what's going on?