Need Help ASAP (Pleaseeeeee)

I have replaced the motor in my Laser. It is a 2.0 NT engine. It ran fine except it was dumping the fuel full force. I was getting about 5 miles to the gallon. I'm sure the fumes I had to breath while driving it couldn't be healthy for my children or myself. I had to quit my job because of this problem. Anyway the fault codes that come up were 12, 13, 21, and 25. I replaced them all and I stil had a problem. So I just finished replacing the wire harness and now it won't start. It's getting fire but that's about it. Come to find out. The wire harness that was used is off a 2.0 turbo. Will that make a difference? Will my ECU still work properly with this new harness? What else can I check so I can get on the road again? Gotta find new job? All advice is welcomed.

Usually only an ECU will trip that many codes. Swap in a known good one and test.

The MAF would be my next point to check.

Please use descriptive thread titles.

does you have a fuel pressure regulator on it? if not i would suggest finding one. that might be your problem. happened to me once and as soon as i put one on (after wasting about 20 gallons of gas trying ot get it started without one) it started up just fine. the motor that i bought didn't come with one so i had to swap in a new rail that did have one.

it was running 80+ fuel psi and it's supposed to have around 45 stock. try getting a pressure regulator or a new one if you already have one.

the turbo wiring harnes didnt work with my 2.0 had to find a n/t then it started right up.

I have a n/t wiring harnes in my basement but its for auto if that is what you need you can have it for $30 + shipping.