Well, I got the Saturn Redline, but...

[stixandstrings]

It has quite a few mods and a severe issue. I could use some help. It has a 2.8 pulley, ported blower inlet and t-body, and an ECU provided by ZZ Performance. Heres the issue.
When you start the car, it idles fine for about 10 seconds. AF hangs between 14.9 and 15.5. With the scanner on, everything looks good. Then, it pops a PO102 code, and the idle drops to an alarming 400rpm, the AF goes full lean (20:1) The MAF sticks at .25 lb/min no matter where the throttle is, the MAP sensor goes straight to 105kp, and the TPS goes from 11% to 35%. The owner replaced the MAF sensor, without a change. I can clear the code, and everything goes back to normal for about 5 seconds. The DTC pops up, and immediately the idle goes back into chaos. SFTs stay at 0%, which seems wierd to me. Thank you in advance for any help.

[Iam Broke]

Is the P102 MAF signal low? Could be a vacuum leak after the MAF, if it's a relocated MAF prior to the TB, on my LNF the indicated flow (freq) was extremely low at idle. I'm not familiar with the supercharged LSJ MAF location though, sorry.

You could check general issues like engine grounds, connector pin damage, ect.

Did it ever run ok with the ECU?

The STFT's stay at 0 because it's being commanded into open loop it seems. What does the MAF freq look like before it shits the bed?

[stixandstrings]

MAF Hz is totally normal until this happens. MAF sensor is still in stock location. Whats wierd is that even when the idle does this, you can drive off, and it runs pretty well. Best I can figure, it ignores MAF and uses the VE tables, because the MAF lb/min signal goes to .25 and stays there. The customer did all the mods, and the ECU at the same time, and it started this as soon as he ran it the first time. I hate blaming the ECU (Ford tech for 16 years) but its looking more and more like it to me.

[Iam Broke]

I would pull the ecu, clean the pins & plugs with contact cleaner, reseat them and try it again if no one has yet. It wouldn't be the first time a dirty pin or two caused an issue.

Look at all the wiring harnesses for signs of pulled wires, damage, ect.

[stixandstrings]

yeah, already went through all the preliminary stuff. Checked all the connectors and harnesses for chafing, etc. The customer's going to ship the ECU back to have it checked first. I really cant imagine anything else he did would cause such an erratic condition.