My buddy has a 1980 F250 that him and his dad have totally restored with updated interior and its really nice. For exhaust he has it dualed up right were the cats would normally be right after the o2 sensor before the original placement of the cats into glasspacks then out the back. It sounds AMAZING, extremely loud when he gets on it and just sounds nice all together.

My question is i wanna do a similiar set up on my 93 F150 XLT but instead y it off the pipe with the 02 sensor down to one pipe into a flowmaster 40 then y it out the back of the truck. Will this hurt my performance? Decrease my mpg? By the way i have a 5liter 302 and theres 2 cats.

Thanks in advance for your help, its appreciated

 

so basically you want to keep it the way it is just without the cats right? if thats the case you'll be fine but you will lose some performance. it will be louder though. i have gutted my front cat and have a high flow maggie where the second cat was and have a flowmaster look alike muffler si/do. when i gutted my cat, the engine itself was quiet. i started it a couple of times to get the honeycomb out of the cat and when i revved it it was quiet. its definately louder with the muffler on it. i dought it would be as loud as your buds truck.

 

so would i loose any mpg with the setup i described above? Or would it be best to just y it out the back of the truck right after the cats without a muffler?

What would be best performance wise and mpg wise? I heard just y'in the exhaust out after the cats sounds pretty mean so that got me thinkin. I've heard alot about removing the cats decreasing mpg and performance. Whats better out of the 2?

Thanks

 

well if you do a single in single out muffler and then split it off, thats not a good idea, i lost mpg and performance with my no cats setup,

and trucks came with 02 sensors in 1980!?!?!?!??!?!?!?!

never seen that before

 

Well its a 1980 body but im guessing that they put newer everything in it so its basically like my 93 just with the older body style. Other then the body style its pretty much the same truck.

 

I would run atleast 1 cat, a hi-flow to be particular, and a si/do muffler, instead of Y'ing off a single outlet muffler.

 

Will i decrease in gas mileage if i dont run any cats or only run one?

 

Damn near all vehicles that run no cats have lost some gas mileage, 1 hi-flow cat will be good.

 

you can do what i did and gut the front cat and place a high flow where the second cat is. or place a y pipe where the first cat is and still use a high flow. i didnt lose any mpg this way and it made it louder.

 

ok thanks. How about if i leave the 2 cats on and just y the exhaust out the back without a muffler, will i loose any miles per gallon that way?

 

idk. but i do know it will be quiet as hell if you use the two factory cats. at least cut out the second cat if you do that. i didnt lose any mpg when mine was like that.

 

heres a link with both cats and y pipe
http://www.youtube.com/watch?v=8PvagUDC_nc
heres one without the second cat and y pipe
http://www.youtube.com/watch?v=DCSPb...eature=related

 

I really like the sound of the 2nd link, got a nice roar when you get on it.