Benefits of 411 ecu swap to run 5.7 now and LQ9 later

[skyhighsami]

I have been thinking about the 411 ecu swap in my 1996 Tahoe. Now it is a 100% stock except for the upgraded injectors. Once I get my other items done on the truck I plan to drop in a worked over LQ9. Now I'm just interested in swapping to an electric fan (so what's ideal and can it be controlled by the EU like the 03+ trucks?) Swap over to the 411 ecu (what is needed and where can I get it?) And finally how restrictive are the factory cats on these trucks? I'm also considering taking the cats off, cut the factory muffler and run all the factory piping. Maybe run turn downs off the muffler or two pipes out to the bumper. Any issues?

 

[zomeizter]

I would wait until you swap the new motor in then do the PCM upgrade and get it tuned for it. I've been researching the PCM swap myself and will be acquiring one soon, donor vehicle is a 2002 Sierra, connectors are different so will need to grab those and re-pin to make it work. Efans can be PCM controlled, factory cats are somewhat restrictive and can become clogged, there are high flow ones available.

 

[Monstar_est87]

Yea just wait on the LQ9 swap... Cuz U'll have to repin the 411 for the 5.7 then again for the LQ9... U could run into troubles doing this...

 

[orange57]

I thought that if you upgraded the the 411 pcm and used an express van factory tune it would be fine, and the if you upgrade to an LSX, if you get the engine harness it would plug right in, and require another tune for the new engine. Am i wrong on this assumption?

matt

 

[zomeizter]

Hmmm, so if i get a express van one it will swap in and no tune required? I like that a lot, my rig is all stock except for M-VIII efan and Flowmaster muffler, on the lookout for a express van donor vic...

 

[orange57]

Hmmm, so if i get a express van one it will swap in and no tune required? I like that a lot, my rig is all stock except for M-VIII efan and Flowmaster muffler, on the lookout for a express van donor vic...

If you purchase one or pull it from an Express Van, it should not need any mods to the engine tune providing the Express Van you pulled it from was also running a 5.7L Vortec as well. If the van was running the 5.3, 4.8 or 6.0 you will need to have it flashed with the 5.7 tune. I also believe, that regardless of the vehicle, you need to have the VATS disabled otherwise it will not start.

 

[JennaBear]

No, the express tune will need to be modified to work. At a minimum the VATS.

 

[SunlitComet]

Speaking for the cats the substrate flow plenty when not plugged. It is the pipes on them and hole sizing that kills the throughput of them.

Sent from my SPH-L720 using Tapatalk