catalytic converter? - yay or nay

[Waggymcgee]

Need a whole new exhaust system. Thinking about removing cat converter and air pump. No emissions required in this state but I am a bit of a tree hugger.

If I do remove should I keep them for any future owner?

Appreciate your input.

[Dave Jeeper]

I replaced my exhaust from the cat back to the tailpipe a couple of years ago. I ordered my parts from Rock Auto and the cat wasn't that expensive. It had an air pump connection on the cat but also came with a small cap that I welded on since I had removed my air pump as part of my Howell Fuel Injection installation. I saved all of the air pump stuff that I took off along with the carb in case a future buyer wants it.


Parts can be had for not that much if you mail order and install yourself.


The original Grand Wag exhaust parts are very thick stainless steel. I only replaced my cat converter because the inside material had cracked and was rattling around. The metal was still good.



My 2 cents.


Dave

[MysticRob]

I really hate the smell of unburned gas exiting the tailpipe so I'm a big fan of leaving that stuff on there just to clean the exhaust gasses a bit, unless you're going fuel injection and it's no longer necessary (points finger at self).

You never know when you're going to need that stuff, like if you decide to sell it to someone who lives in Smogifornia, etc. I'm keeping all my smog stuff in storage just in case. I was joking with Dave that you never know when/if that stuff will be so rare it fetches thousands of dollars like old Thermactor gear on Boss 429s.

[tgreese]

Supposedly there are replacement cats that do not need the flow of fresh air from the AI pump. Might be what you are looking for.

Also supposedly - the air pump will rust internally and freeze up it you remove it and put it on a shelf. I've read you can dunk them in kerosene or immerse them or something and they will be preserved.

Removing the extra systems probably will prevent sale of the car anywhere that requires a visual, like California or places in Arizona and Nevada ... maybe others.

[61Hawk]

I found a replacement that didn't need the air pump, direct fit in with a brazed on cap over the air pump inlet. Installed it, pulled the air pump that had recently locked up, and haven't had a problem since. The old catalytic converter was the original and when I pulled it off was completely hollow inside. I can now put my nose up to the exhaust pipe and breath without any gas fumes.

[Herk]

The modern honeycomb catalysts have basically no restriction and cost no power. The original pellet type catalysts that our vehicles came with were another story.


The air injection system does use a little power and clutters up the engine compartment. Modern cats will fire off fine without it if it is mounted in the original location.

[Tripwire]

yes install the Cat, you dont need outside air and the planet will be a bit better for it - as said they offer very minimal restriction

steve

[ProTouring442]

I recently installed a cat on my LY5 swap. While the exhaust on my swap is probably cleaner sans cat then a stock Wagoneer's is with it, I like the lack of exhaust smell, plus it quiets it a bit.

[Waggymcgee]

I kept the cat new exhaust. Flow pac. My little one said, the jeep sounds furious. Hell yeah.

[rang-a-stang]

I kept the cat new exhaust. Flow pac. My little one said, the jeep sounds furious. Hell yeah.

Does this mean you put a new cat on there? A furious Jeep is much better than Jeep that sounds like a Prius...

[oregonphil]

So just for discussion sake, if we agree that cats are better for the environment, would there be any downside to voluntarily installing one on older cars that did not originally come with them? Not counting the extra cost and labor.

[ProTouring442]

So just for discussion sake, if we agree that cats are better for the environment, would there be any downside to voluntarily installing one on older cars that did not originally come with them? Not counting the extra cost and labor.

Yes! An engine not properly tuned for a cat can cause the cat to overheat.

[Heavy_Metal_Thunder_81]

I'll be running dual cats on mine soon.

[Waggymcgee]

Does this mean you put a new cat on there? A furious Jeep is much better than Jeep that sounds like a Prius...

I kept the cat that was on there which is just a catco, but she is running great. Had been stalling primarily when turning right so thought it needed carb work. Did not want to mess with carb til I had the extra fuel tank working right. But, she has not stalled since replacing all the fuel lines. Hooray!

[rang-a-stang]