Hey everyone, I have a 5.8L 1991 F150 that I recently acquired from a friend. The truck was originally a California truck, but has been registered in Nevada for some time, during which an aftermarket exhaust was installed and the cats removed. I live in California and am trying to figure out how and where to install the cat(s?) and how to hook up the smog pump. A diagram, or even an explanation of how it all goes together would be extremely helpful. I bought a Haynes manual, but it doesn't actually seem to go into any sort of detail about these components and how they're installed on the various engines. I tried to go to a Ford dealership to obtain a diagram of the exhaust system, but since the truck is so old all they could give me was some cryptic, useless drawing. Any help would be greatly appreciated, I don't even know if there are 1 or 2 cats. When I go to buy them online, some sites say 1 and some 2.

 

The Haynes has all that information.

 

This might help, I have more diagrams if needed, just let me know. There are 2 catalytic converters and you can see the tube assembly between them. Between them is a check valve for the exhaust. The last diagram gives you the general routing of the smog system, its just a generic picture.

 

Be aware that California requires you to buy California ( CARB ) certified replacements cats. 49 state legal and used ones are not legal. Having said that though its rare that anyone will inspect the cats that closely unless they have a reason to.

 

Thanks, those diagrams are definitely helpful. It looks as though I may be missing the air pump inlet silencer/filter and thermactor dump silencer. Being that those are silencers/filters I'm not sure how essential they actually are to the emissions performance of the truck

 

Functionally they aren't essential however emissions laws are determined by politicians. All original smog equipment or CARB certified replacements must be in place to pass the visual inspection. Now how closely the inspector looks is on him however an inspector caught falsifying can loose his licence and have his equipment confiscated. I'm currently working on my inspector/repair license in California. You should be able to find those parts at any junkyard or online cheap. People pull them all the time to make the engine bay less cluttered lol.

 

I will also need to purchase the catalytic converters. Does anyone out there happen to have some for sale that maybe they pulled off and aren't going to use anymore??

 

I just happen to have the cats and y pipie from a 95 302. Nothing wrong with them, I just recently modified the exhaust. The y pipe was cut for removal but could be repaired. Yours for the cost of boxing and shipping from Utah. It seems fairly heavy so it might not be cheap, I'll take a picture tomorrow and also get an idea of what it would weigh.

 

That would be great. Are the 5.0 catalytic converters interchangeable with those for the 5.8?

 

the Y-pipe off a 302 wont fit on a 351...

different widths...

i would just find someone in Nevada to register the truck at there address.. your looking at more trouble than it's worth IMO....