04 TB, 4.2 engine. Codes P2135, P2101, PO4555. I replaced the air horn a year ago, ran fine until a month ago, replaced throttle pedal assy a month ago. I can drive the TB for a while, then goes into reduced engine power. I can turn off ignition, restart, and all is good for a while, sometimes a week or more, sometimes a few minutes. Code P2135 tells me either the throttle pedal or air horn not connected. P2101 relates to about the same thing. PO455 is excessive air flow in EGR. I did notice the cat con makes a rattling sound like a loose baffle. A friend tells me that is the whole problem. I don't want to replace the whole cat con and pipe if it is not needed. I already have about $300 in the air horn and throttle. This TB is getting to be a pain in the ass, costing more money than the damn thing is worth. It only has about 130K miles on it. What can cause all these problems???