Ok.. Fired my truck up for the first time a week or so ago and I cannot get these codes resolved.

Truck specs.
'99 with a '02 Nelson tuned PCM.
'04 stock LS6
4l60e
Shorty headers w/ cats and O2 sensors
MAF is from the vette, not the truck (would this cause any issues)
No EGR.
dbc throttle body appears to be from an f-body (compared to pics of a truck/f-body) that I purchased from a guy on ls1tech who ports/polishes and powder coats throttle bodies.


I'm attacking the P0507 first.
What I've done to date:
Replaced the intake gaskets and torqued down as required.
Removed the IAC and checked it over - checked for loseness, pushed in the plunger, etc.
Cleaned the IAC and inside of throttle body (where IAC mounts)
Performed idle learn procedure several times - after motor was at temp.

No differences. Engine still idles at 1100 rpm and when I put it in gear, the rpm goes up and comes back down but only to around 900.
When I rev the engine, it's responsive but when I let off of the throttle, the rpm's slowly drop back down but never below the 1100 idle.

As for the P1336, I don't have a scanner that can perform a crank relearn and I can't drive then thing to a shop cause I have no brakes! Don't have a scanner that will cycle the ABS pump so I can correctly bleed the brakes.

Would not having the crank relearned be causing my P0507 issue too?

 

Has the hole in the throttle body blade been drilled/enlarged?

 

That, I'm not sure of - not by me anyway. I'll shoot the guy a pm (over on ls1tech) to find out. Stay tuned.

 

If you did one of them exchange type deals you may have got a throttle that was drilled for a cam swap.

 

Good point. Haven't got a response from the guy I bought it from - he hasn't logged in since 2011 so I doubt he will respond.

I was able to get a measurement with my dial calipers. Hole appears to be around .155" and I was able to just get a 5/32 drill bit in the hole.

 

Dicking around with this thing last night after testing the circuits, I pinched off the brake booster hose and viola... the idle went down and appears to be stable. I'll be replacing the brake booster check valve first and then brake booster this weekend. Who woulda thunk it. Crossing fingers.

Also, had a friend of my dad's drop by last night. He performed a crank relearn and cycled the abs pump with his fancy-*** high dollar Snap-On scanner. I have brakes now!

 

Fixed! Bad brake booster.. Oh, and the evap code... didn't have the connector plugged into the vent valve solenoid. Living right today... knock on wood.