2002 5.4 Crew Cab

I have "dual exhaust", but not like you are looking for.

I have a Flowmaster 40 Series Delta Flow one in two out behind the stock cat. 2 1/4" pipes with two 3 1/2" (18"?) angled out behind the rear wheels. Cost was about $200.

Sounds good from the outside, but I'm not 100% happy with the sound inside. I'd get the non Delta Flow if I did it over again. I thought it would help the gs mileage a lot, but it it didn't very much if any.

I had a 95 Bronco 351 and I put on a 40 Series non Delta Flow and I went from getting about 425 miles to a tank to about 475.