So I was having issues with the truck stumbling a bit at idle. CEL was coming on with the codes P0172 and P0300. Just recently replaced all the plugs and coils. So I replaced the gas cap, put a tank of 91 octane and injector cleaner, pulled apart throttle body and cleaned it, cleaned MAF sensor and cleared the codes. The truck seems to be running good now, but when coming to a stop it stays at around 1,000 rpm then drops real fast. It never did that before. Any ideas? Is it just because the computer is used to a filthy throttle body?

 

Fixed! Disconnected the battery for a bit. Problem solved.