I have an 04 xe titan with air box mod and stock 3" exhaust with flowmaster original 40 installed. I have 89000 miles on it and sometimes when I romp on it when I get to the higher rpm's it fights me a little like 4000 or so and up. Was wondering if anyone else has experienced this at all with their trucks. Thanks for any input. I have definitely learned alot from you guys about my truck and this site is pretty cool.