Throttle pedal/body loose connection (?)
 

Need help with my '04 v70, I bought the car a few years back and I love it but for about a year and a half I have been battling throttle/limp mode issues. I have replaced the trhottle body with a remanufatured one, and replaced the pedal with a brand new unit. I believe it may be a loose connection somewhere in the system as it seems to happen randomly, but more frequently over bumps and vibrations. It has thrown codes p2135, p0121, p0221, and p0638 along with other throttle codes and codes that my scanner can't read (CEL and reduced performance message pops up but scanner says no codes found). Any help would be greatly appreciated as I would rather not have to worry as to whether my car is going to randomly kick in to limp mode going down the highway, and I would rather not take it to a shop to get work done. Looking specifically for where the throttle pedal harness plugs in to the computer or any common spots where wires may become broken or loose to cause such issues. Thank you in advance.