weird noise

[dshriver05]

so i need some advice. my truck is a 05 250 with the 6.0. mys include a diffrent airfilter(airraid i think)stock dp to hollow cat to 5inch stacks and a superchips maxmicrotuner. the problem is with it on i hear a noise coming from under the hood when the truck has to work a little like pullin a hill on the interstate or a hill around here when it stays in od. it sounds like a squeel or something like that that comes in little bursts. it does it more with the superchips on but also does it with the truck back to stock. any ideas would be greatly appreciated and thanks in advance.

[pitamarillo84]

im not saying that this is it but i just fixed a similar problem where id have howl/whistle/exhaust noise.... from under the hood and it was the passenger side up pipe they fail at the flex section and make a noise at different rpms and speeds if i were you i would just crawl under the truck with a flashlight and check that flex joint while the truck is running may save you some time hope this helps good luck