I found this doing some research it might help you
Need help!! Car is at stealership!! P1518 code - Page 3 - Corvette Forum

 

God I wish I could fix mine with an ignition switch. My truck starts, runs, cruises, part throttle fine. But when you go WOT and hit higher RPM's, bam it goes into REP mode. Always pops the P2101 code for a restricted throttle blade. A log shows the blade moving a few degrees right before it trips.

 

If I would have had this problem for as long as you I would have burnt it to the ground by now.

 

I tell my GF every day I am going to smash the truck with a sledge hammer. I wish I would have never layes eyes on it now. It isn't even fun anymore. I can't even get into the gas without going into REP mode. I would really like to find the engineer that thought there shouldn't be a cable operated TB on vehicles anymore and kick the **** out of him.

 

bump... did u try an ignition switch like the vette link says?

 

No, from everything I have gathered, the engine is moving too much air, and the TB can't handle it. It runs fine until you get into the gas.