Would adding a High-flow cat be a cheap way to gain performance?

[nathanours]

Hey everyone, I was just curious if I'd see much, if any, horsepower gain on a Gen 3 2.2L camry by switching to a high-flow catalytic converter. A mechanic suggested it to my friend, and I was wondering if that would really make much difference?

[quangtran89]

If it does it won't be much. You can always dyno to find out. Do a base run and then run again with the new cat to know for sure. On my old Camry I installed header, intake, and a custom exhuast with a magnaflow muffler, I didn't feel any noticeable gain.

[Stillrunning]

It's probably already a "hi-flow" CAT.

[Zembonez]

It's very unlikely that ANY performance gain will be seen by replacing the cat. Most manufacturers market their products as "high flow" as a selling tool. What they don't tell anybody is that manufacturers already install "high flow" cats when the car is built.

[Pvt-Public]

What they don't tell anybody is that manufacturers already install "high flow" cats when the car is built.

Just look through any Cat. you can see right through it.

[nathanours]

Interesting, thanks for the responses.

[dorifuto.boi]

if your catalytic converted has been melted, then changing it out (for either a stock replacement, high flow, or test pipe) will give you power gains.

[nathanours]

How do I tell if it has been melted? Any easy way to take it off and check?

[BMR]

I watched a guy check my F150 for clogged cats (it has two). He drilled a small hole on the upstream side. Attached a pressure gage to the hole. Started the engine. Then he'd punch the gas briefly, letting it rev up and drop back to idle. The pressure would build quickly, and took a few seconds to drop back down. That delay = clogged/melted down cats. Pressure should drop immediately. When he was done, he welded the hole shut. I'd guess any exhaust shop ought to be able to run that test; shouldn't cost a lot.

[RichieRichJP]

Catalytic converters have baffles in them regardless. I doubt you'll notice any gains or even get any. Maybe 1-2hp, but that seems optimistic.

[BMR]

I agree. Unless it's clogged or melted, replacing it won't gain much.

[mazdaverx7]

survey says.....you have a 135hp 2.2L 5S-FE I4..replacing the converter with a claimed hi-flow catylitic converter is not going to net you any newfound power. it may help the engine run smoother and get better mileage as the original converter may be starting to break apart and clog or start to melt...literally..