alright my 93 f150 5.0 had 2 cats on it when i bought it. front di/so (i gutted out). rear si/so (replaced with high flow maggie). my lmc truck catalog shows that the 85-94 f150's with 5.0's are only suppose to have the one si/so cat and a y pipe where the front cat was. does anyone else with a truck similar to mine have 1 or 2 cats? i just want to know how my setup is suppose to be? its not a california truck if that helps.

 

I think most 49 state 5.0 - 5.8 F-150 trucks have (1) DI/SO, then (1) SI/SO with air injection inbetween. That's what mine used to have anyway.

 

Right and they perform different functions. The front converter reduces oxides of nitrogen, the rear converter oxidizes carbon monoxide into CO2. If you replace the pair you need a "3-way" with an air tube to maintain the same functions.

 

ok thanks. well the reason i asked was because a dot officer or whatever they are pulled me over. he clocked me at 58 on a 55mph road. he knew i was going faster but thats what his radar got me at. so he checked out my truck and tryed his best to get me for something else. he checked if my tires were to big or if my rear bumper was too high off the ground and then he checked my exhaust and felt my front cat wasnt hot so he knew it was gutted. i said i gutted it so i didnt have to buy a y pipe and this is how its suppose to be. i had my lmc truck catalog on me so i showed him what it said the stock system was suppose to have and he was really pissed off then. he just pealed away without saying anything else. so i guess i got lucky there.

 

Can you explain how you gutted the first cat? The tubes into it are curved so it is not easy to jam a rod in there like a normal cat.

 

i cut the pipe directly behind the cat and just used an air chizel to beat the insides all up and then started the motor a couple of times to get all the metal out of it before welding it back together. pretty simple.