I have a 2005 Chevy Silverado originally came with a V6 I did a LS 5.3 swap the 5.3 came out of a 2001 GMC Yukon with a drive-by-wire and i mounted the 5.3 to my NV 3500 5 speed manual transmission I use the factory 2001 harness that I had rework to stand-alone and the factory gas pedal with the TAC box and the blue and red ECU that I had reflashed all security system removed the truck starts up and idles but when you accelerate soon as it hits 2000 RPM it just bogs out and wants to die out I have the OBD2 port hooked up it's not giving me any codes any help on what could be wrong

 

I know the TAC box has reference throttle % stored in it. If that doesn't approximately match what is stored in the PCM then the TAC box will go bananas. You could try ensuring your tune has the correct DBW table loaded in it for your year/application of your TAC module..

 

The green/blue connector type harness and ECM from a 03+ dbw truck/suv is the correct and easiest swap for your application, it's plug & play. You match the year of the truck to the harness (green/blue) and ECM not the year of the (red/blue) engine to the harness of an 03+ when doing the V6 / V8 swap. Not saying you can't get there but...

I had the opposite issue a 99-02 truck with a 2005 engine, ecm and harness. I asked Brendon at LS1swap.com if it would work, here was his reply.

 

the tac module came with the swap but did not come with the track module harness I had to go to a Pick Your Part and get it out of a 03 Yukon it fitted and plug in you think that might have anything to do with it?

 

so if I switch up the setup from a 00-02 red and blue ECU harness to a 03 to 06 harness green and blue connectors and ECU it's probably best if I go to a pick your part or junkyard and get the whole harness what the fuse box and ECU gas pedal Tac box from all the same vehicle?

 

Yes it would be best to use a green/blue PCM in the 05 truck along with a matching TAC module. That will also ensure all of the serial communication works properly.

 

if I use the OEM 05 harness isn't some of the connectors different from the the 01-02 5.3 engine like injectors ignition coils

 

I am not sure if this is relevant or not but I am running the 02 tac module in my 05 truck with the 05 truck pedal. Wouldn't the 02 TAC work with the 01 harness as well?

 

I just got a original 03+ blue and green harness complete with fuse box.ECM throttle body I know people say that it's plug-and-play mut isn't some cutting and splicing. Required to get power?

 

I just installed. A harness and ECM and throttle body from a 03+ Silverado green and blue connectors Plug & Play But it's still doing the same thing. Idles fine. But bogs out at 1800-2000 RPM I checked the fuel pressure. At idle its at 48psi When I rev it up a little bit it drops to 45psi