Why would my lt1 be running rich. It has a little work done to it. Long tube headers, air intake, tranny work and rear end work.

 

Is it tinged for the LT headers?

 

i don't know if it is tuned for having the lt headers or not I did put the o2 sensors into the headers

 

Any codes?

If it is not tuned it can get a false lean. Scavenging at high rpm, lower low rpm velocities, and all that jazz can cause a false lean condition.

 

Only codes is low freon and evap

 

Whats the year, model, and trans type? Maybe put a scanner on it and do a data log.

 

93 lt1 z28 with an auto trans

 

I'm not sure if anyone else has had the same problem however, when I ran a 160* thermostat untuned my car ran really... REALLY rich and got horrible MPG. My guess would be where the computer is looking for a certain temperature the car was basically running choked and rich.

 

There's the magic numbers right there.....

You CANNOT use the stock O2 sensors on a '93 with Longtube headers. The stock single wire O2s are non heated and when you move them downstream in the headers, they don't get hot enough to operate correctly. You need to buy 1994 LT1 front O2 sensors and the pigtail wiring and wire them up. They are 4 wire sensors that are heated and will give the ECM better readings. I can't remember the pinout numbers but 1 wire is a keyed 12V source, 1 wire is a ground, and another is the ECM wire that goes to your stock O2 plug. The fourth wire isn't needed.

Search Fastbird93 on here, he has a writeup for this conversion. My car ran soo much better after doing this.

Edit: Found one thread that should help, I should have documented when I did mine.
https://ls1tech.com/forums/lt1-lt4-m...t-headers.html