problem need help

[kst3v3n]

This should be easy to nail down.
If this ran in the 57 then it should run in your truck unless :
1. The computer was swapped and its not the one that was running that engine in the 57.
2. There was a stand alone VATS unit that you didn't get. (iirc early models could be bypassed like that)
3. The guy never had the check engine light in the 57 or didn't care about the codes.

Fuel pressure check, a temp hot wire to fuel pump and a noid light will tell you if the Injectors are being shut down by the VATS or just low on pressure.

Since you have a security code, is suspect VATS, and the other codes is suspect a different computer.

This could have happened:
Hey man I just sold my engine out of the 57.
Really, didn't you have a custom tune on that computer?
Sure did, cost me a few hundred bucks too!
How about you swap me this computer and give me the one out if the 57?
Sure, here you go.

Get the picture?

[Bad 454ss]

yea i know the guy that i got it from he is going to look in the car later and see if there is a bypass that he overlooked when he took the motor and harness out. He also didn't build the car his neighbor bought it a while ago and wasn't into the new more complicated ls1 and just went to a carb 383. but there is still the evap code and an anti theft code so obviously it wasn't tuned properly so im just going to get a new tune once i build up the money for it.