My 99 7.3 seems under powered and down shifts on small grades compared to a 95 7.3 that I had previously, also the milage is not as good. What I am looking for is some recommendations to help these issues. Every one you call wants to sell you a tuner, exhaust and an intake system. My 95 was completely stock and pulled fantastic.I had the truck diagnostic checked and it came up with no codes.I dont know what they changed from 95 to 99 but somethings different. Any suggestions would be appreciated thanks scott.