Wiring/ECU for 5.3 ls

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Apr 6, 2020 | 04:25 PM

Wiles111

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Wiring/ECU for 5.3 ls

I’m just starting on an engine swap. Got a 99 Firebird v6 and was wondering that if I swap everything from the 5.3 donor including wiring harness with its ECU, will I have to reprogram it?

Apr 6, 2020 | 05:22 PM

Che70velle

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Quote:

Originally Posted by Wiles111

I’m just starting on an engine swap. Got a 99 Firebird v6 and was wondering that if I swap everything from the 5.3 donor including wiring harness with its ECU, will I have to reprogram it?

Welcome to LS1Tech! As long as it’s the matched ECU from the donor, you won’t need to tune it, other than removing VATS. VATS won’t allow the car to run. Stands for Vehicle Anti Theft System. Basically the computer thinks the car was stolen. Now...tuning won’t be necessary, however you will find power with a good tuner. Your gonna have to change the intake on the 5.3, from a truck intake to a car intake, so a good tune will only help you make power.
Ask questions over in our PCM Diagnostics And Tuning section. Lots of smart guys over there to help you with anything you need.

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