High RPMs!

So i've got this 2002 F150. Replaced the COPs last winter. New plugs and wires. Changed the injectors, fuel pump, and hollowed out the catylytic converters. Today i drove 20 miles down the highway. I stopped at the local store and put it in park. When i put it in park...it rose from 1000-2700rpm. Put it in neutral, and the rpms never came down. Put it in drive and got one hell of a jerk! Shut it off and restarted. It ran fine until i headed 20 miles down the highway again and it happened again at the house. Whats causing this? Vaccuum Hose? Bad air/fuel mixture? Something with throttle body? I just don't know! HELP!!!!

First off you wil get a check engine light with what you have done to the converter. Next you wil probably find the Idle Air control motor or the harness to the motor is the problem. I have seen the wire harness break and have an intermitent open between the ecm and iac. Also check the operation ofthe TPS. You willl need a good scanner or DVOM. Scanner works best

I did get the check engine light. I need to get the fake O2 sensor. They harness seems to be ok. I didn't get into too much detail looking it all over cuz I had class today, but that could be a possibility. Cleared all codes with my scanner...but it didn't read anything other than the O2 sensor...then again its not a spectacular computer either...