Hi guys Im New to the forum and was wondering a few things. I have a stock '05 F150 with a 4.6 V8, K&N air filter ( not cold air intake), and a 2" Flowmaster cat back exhaust, and Pretty much an outdated Super Chips ( Multi Make) tuner. The truck feels like it has little to no power on the bottom end, and it suffers at mid range also. The truck has 197,000 miles on it but still runs well other than the lack of power. First question - with the 4.6 would it be worth the money adding shorty headers and hi flow cats? 2.- How would that affect my emissions? And lastly can you guys recommend some things to look at to help restore the power?