2004 Tahoe Z71 163k Miles. Haven't had any issues for a while with the truck, about 800 miles ago I was having issues with rough idle at stops. Tonight cranked a warm engine and the engine light came on with reduced engine power warning and a rough idle. Drove 20 feet and turned off truck for about 20 minutes. Cranked truck back up with engine light but no other warnings and idle was fine, pulled code of P0220, Autozone said throttle body. Any ideas or is this right on?