Hi, my 2008 Express 1500 4.3 with 212k. Got a check engine light P0641 that goes into an "Engine Reduced Power" (computer induced half throttle) warning on the dash, on Monday, but was intermittent. Decided against going to the dealer, went to it to my friend's small shop. I removed the passenger seat to make room to remove the doghouse. We hooked up a scanner, key on, not running and started moving and tugging the engine harness because it was intermittent. We were able to make the error happen wiggling the harness, a bundle of about 30 wires. Then found the problem three or four wires were bare on the bottom of the main bundle passenger side toward the front of the engine touching a steel bracket. The van was from Florida and most of the wire loom protectors were mostly gone and deteriorated. Called for a price on a harness, $800. Decided to repair, but could not get to the areas without basically removing most of the harness. The mechanic disconnected all the stuff, top and bottom, and transmission, but kept the harness connected to the large junction box. He found seven wires that he cut slid on a shrink tube, spliced soldered and heated the shrink tube. All new wire loom, freshened up the heat tape areas, then put it back together, $600 total.