Question about Magnaflow High Flow cat on otherwise stock truck

[sneakingfart]

Where in NY are you? I have the stock cats I took off my 99 Yukon.

I'm in Long Island.

 

[sneakingfart]

IMO no benefit to the high flow on a stock application.

A while back one of the stock cats went bad on my '06 SS, rattling like crazy and finally blew into chunks so the exhaust sounded really dumb with one cat and one blown. Local performance exhaust shop welded in a universal fit Magnaflow for about $150. Can't beat that when the "direct fit" stuff is almost $800.

Richard

Thank you, I haven't thought about going that route.

 

[sneakingfart]

New York State passed a law within the last year that any replacement cats has to either be OEM or have a CARB EO number. I live in New York also and Summit won't even ship a universal federal emissions cat to my house.

https://www.dec.ny.gov/docs/air_pdf/amccguide.pdf

Yea, same problem here. Good thing Is, my parents live in a free state and they are coming to visit soon. They can drive it up for me.

 

[sneakingfart]

Must live in a populated area. They don't give 2 ***** where I am. Long as check on light isn't on, it's good.

It's the same on Long Island, problem is nobody will ship here. I have a way to get it, but I have no desire to make a non-CARB vehicle CARB compliant.

 

[sneakingfart]

If the high flow version comes with a 2.5" head pipe and the non-high flow has the weak @$s 1 7/8" head pipe then yes, it's worth it even on a bone stock application. Is there a difference in head pipe sizes here?

That's something I have to look into. I can tell you that going from a stock 2" pipe to the high flow 3" on my Civic Type R made a huge difference in turbo spool and pressure.

 

[HawkDsl]

I can't remember the name of my cat, I want to say dynamax or something like that.. probably out of biz.. but it works, and it's been on there sense about 1995. Got it from summit back in the day. It's the honey cone style, with no mufflers at all (2 into 1 into 2). Not loud at all. My local performance shop built me a one off because the headers I bought (Mesa Headers) were for automatic, and they needed to be redone.

 

[Schurkey]

Far as I know, there's two kinds of catalytic converters.

GM's original "pellet" style. Theoretically rebuildable--GM had a process for dumping out all the "old" pellets, and replacing them with "new" pellets, on-the-vehicle. In real life, the screen that held the pellets in would rupture, and then all the pellets would wind up in the muffler. Used to be somewhat common to see cars idling at the stoplights, spitting a pellet out every now and then from the end of the tailpipe. The mufflers would rattle like maracas when you'd smack 'em with your fist.

Ford, and everyone else's monolithic "honeycomb" style. Non-rebuildable.

The monolithic, honeycomb style flows better than the pellet style. A "high-flow" catalyst is one that has the honeycomb structure instead of the pellet structure, and maybe has less catalyst material inside than OEM. So pretty-much every aftermarket catalyst could be advertised as "high flow" especially if it's replacing an OEM pellet-style.

 

[L31MaxExpress]

The stock GM cats, even the dual 3" models are restrictive. High flow cats and a muffler swap gained more than tuning on my stock engine.

 

[Supercharged111]

Far as I know, there's two kinds of catalytic converters.

GM's original "pellet" style. Theoretically rebuildable--GM had a process for dumping out all the "old" pellets, and replacing them with "new" pellets, on-the-vehicle. In real life, the screen that held the pellets in would rupture, and then all the pellets would wind up in the muffler. Used to be somewhat common to see cars idling at the stoplights, spitting a pellet out every now and then from the end of the tailpipe. The mufflers would rattle like maracas when you'd smack 'em with your fist.

Ford, and everyone else's monolithic "honeycomb" style. Non-rebuildable.

The monolithic, honeycomb style flows better than the pellet style. A "high-flow" catalyst is one that has the honeycomb structure instead of the pellet structure, and maybe has less catalyst material inside than OEM. So pretty-much every aftermarket catalyst could be advertised as "high flow" especially if it's replacing an OEM pellet-style.

Far as I know, the high flow cats have bigger individual honeycomb openings. And of course the cheap ones have less precious metals and stuff that makes a cat do what it does. You'll sometimes see them advertised with cell counts. Lower cell count = higher flow and less catting.

 

[sneakingfart]

Thank you for all the info everyone. I think im going to roll the dice on the magnaflow high flow cat and hope it lasts longer.