I did a "basic" port/polish job on my tb and after putting it back together I get a check engine light and a "reduced engine power" signal on my info display on the dash. I have ported/polished around 50 tb's on f-bodys with no problems. Anyone have a suggestion? It's on an 04 SS silverado.

 

Check the wires to the throttlebody and the TPS.That's what warning you get when you're throttle by wire is messing up.

 

Cool, I'll check that. BTW. What's the best way to reset the PCM on these trucks?

 

key on-remove PCM fuses in the fuse box under the hood(two i believe)-wait about 10 minutes-key off-reinstall the fuses

or find someone with a scan tool.

 

That would be PCM B and PCM I

 

Don't the new fly by wire truck TB's have that "tongue" looking thing in them behind the butterfly? The electric TB's don't have a hole in the butterfly so the computer opens the blade slightly and that "tongue" is there to help the air flow at idle. I remember reading here that someone did a port and polish job and removed that and it gave them the same problem.

 

Yeah he had the SAME problem...maybe he will post here.

 

I had a stock one opened up to 80mm "new plate and all" and I got the same code.

 

Wel I let it sit overnight with the battery unhooked. I pulled the tb off, doublechecked everything , reassembled and it runs fine. In fact, it runs a bit better now with the ported/polished tb and coolant bypass. Thanks for all the help.