Anybody added a cat?

[Johnnyb]

I was goofing off watching YouTube the other day and I saw a guy restoring an old Jeep having a metallic core catalytic converter added to reduce exhaust odors.
My EB is fuel injected but it has a soft top and in some situations the exhaust is noticeable. The more delicate might even call it objectionable. My AFR is about 13.0.
Since I'm in for a new exhaust system anyway I was wondering if one of these high flow metallic core cats might further improve odors?
https://privatelabelmfg.com/collect...flow-performance-metallic-catalytic-converter

https://www.summitracing.com/parts/...R2jZY091nuyGroN6qdQ4aKQo4SkADVjYaAgKDEALw_wcB

-JB

 

[fordguy]

What EFI? I have added a cat and Garry programmed the ecu for purge valve and canister. It is running pretty clean, but I am still building not driving.

 

[399strokerEB]

I've been thinking of throwing one on mine, even with the efi I still get a little smell rolling back in when I have a window down.

 

[1969]

I am going to add a generic cat from Summit to help cut down on the smell. Figure I’d find a universal one for a V8.

 

[Johnnyb]

What EFI? I have added a cat and Garry programmed the ecu for purge valve and canister. It is running pretty clean, but I am still building not driving.

ProFlo 4

 

[fordguy]

I am running stock explorer efi

 

[Bruners4]

Not quite the same but relevant. I put a Bassani full system on my '96 with a 5.8L, headers to tail pipe w/o the cat. Drove it for about 2 weeks and took it in to add a cat. I didn't notice any performance or fuel mileage difference. But the exhaust smell was so much more tolerable.

 

[904Bronco]

Yes, I have added a Cat to my Explorer builds. The Wife complained about the gas smell when the hardtop was off. It will clean up the exhaust and muffle down the exhaust sound some. I have a two into one exhaust system. (pictures are from my 69 Bronco)

I have been using the Cat model for 1996 Ford bronco with 5.0. The Walker Part # I have used has been discontinued at Summit. (WLK-80708) It was considered a CAL CAT, which means they would ship it to me in CA.
Summit advises that a MagnaFlow MPE-51206 ($194) or MPE-99206HM ($178) will fit the application, but they are 49 state replacements, so they will not ship either one to me in CA. Good thing I stopped by the Reno warehouse on a road trip to Idaho last month. The difference in the two is based on the webbing material inside.

Same hoops to jump through for my 79 Bronco, only 3 replacement cats are listed to be acceptable to the state of CA. One is discontinued, I was able to get one of the two remaining at Summit and picked it up at the Reno warehouse as well. This state doesn't make things easy...

 

[Johnnyb]

Yeah I have been considering options for exhaust systems and I appreciate the pictures @904Bronco . I think I'll probably stick with duals but I am definitely considering my options. I have some considerable space challenges over the rear axle and around the 23 gallon tank. My present system is limiting upward travel and pinching my shock absorbers.
My understanding for catalytic converters in aftermarket applications is that it's better to use a metallic core when you don't have a post cat oxygen sensor. Supposed to be more tolerant to temperature ranges.
It'd be great to clean out the smell as much as possible especially given how drafty a soft top is by very nature, not to mention when you're running with the top down.

THX,
JB

 

[Jakedog]

I've thought about using a cat as well. Right now I'm duals with side exits before the rear tires.
Before I do that I'm thinking of going to a single exhaust with a 2 in 1 out flowmaster. 3" on the exit.
I had that set up on my 75 and I didn't have excessive exhaust smell.
Worth the try.

 

[Broncobowsher]

Modern cats are nice and high flow. Not the restrictive monsters from the 70s.
I see no reason to not run one, even on old stuff that didn't have one before. With EFI the A/F will stay close enough to keep it functional.
You do have to watch heat, they get hot. 13:1 A/F might be an issue. If it can be a little leaner, get a little more oxygen into the exhaust to take care of that excessive fuel, that will really help. 13:1 is fine under load, try for closer to 14~15:1 off load. Best power is slightly rich, best economy is slightly lean, best emissions is in between.

Heads up, this will not fix a cold start smell. The cats only work when they are warmed up. It will take a little bit of running to get one warm enough to work. Modern cars shove the cat as close as possible to the engine so they will heat up faster. Look at 1 ton and greater trucks from about 30 years ago and the cats were after the muffler so they were not too hot (big work trucks are designed to pull at full throttle nearly continously). For your wants, put the cat where it fits. Don't be concerned about getting any specific distance from the engine. The Bronco is a short enough wheelbase you really can't place it too far back. Anything in front of the muffler will be a good location.