I changed my EGR valve...and was surprised at the $120 price tag....but it was easy. I also cleaned out the tube...but that was easy because I had the intake plenum off. Take off your EGR valve, clean it up with B12, clean the tube with B12. Take off the throttle body (not really that hard, but you will need to replace the gasket afterwards) and take the TPS sensor off the bottom. Clean it up, clean up the throttle body. Whole task: $20 in B12 and gasket and gasket sealant. Time: Two hours disassembly and reassembly....few minutes cleaning crap up. Difficulty: Easier than forking over $500.