lemonth68

Ready to do some the exhaust work but not sure what I want to do. We don't have emission testing here so I'm thinking of removing the cat and welding a pipe in its location. Running stock cat and a dynomax muffler a friend gave to me with a turndown right now. Seems to be a lot of different opinions with the cat removal. Would think the truck would run better without it since I only have one o2 sensor before the cat and not one after, but not sure what I want to do. Don't have the money for headers right now. Just want a good sound.

RSR

"Test pipes" with flanges are easily found and installed. It's a violation of federal law to remove your cat (Clean Air Act), so it might be a good idea to keep your exhaust system ready for a quick swap back in.

This dyno found just 1 hp difference between a test pipe and magnaflow metal core high flow cat -- and the test civic has basically the same HP as a 3vze...

http://www.importtuner.com/features/...l/viewall.html

lemonth68

Thanks, went fishing this morning and on the way the weld broke holding the muffler, Right now its tied up on the frame. I'll be going to the shop Tuesday after work to see what they can do. Test pipe would be nice if I ever wanted to put a direct fit cat back on.

edeslaur

RSR's point, and I agree with it, is if the current cat is working, leave it in. It's not costing any amount of HP you'll actually notice, and it's helping clean the environment. Consider it Treading Lightly.

Regarding sound, that's very subjective. I have a buddy who loves his Flowmaster. I find it tinny and annoying on the road. OTOH, I have a Flowmaster in my motorhome, but the Magnaflow resonator makes it sound wonderful (I have an awesome shop here in SoCal, but this was the first exhaust they did for me and I was sure they were going to be wrong about that FlowMaster). Discuss what you want with your shop. A good one will hook you up with the right muffler for your tastes.

Some folks like the raspy Jap sound, some want a rumble. The cat's not going to make a difference on the sound, really.

If you're looking for power, a header and good muffler will be the place to start. I've been partial to Doug Thorley's, tho I haven't had one on a Toy.

RSR

Not sure that I concur that the stock cat isn't affecting performance. Over time, cats get clogged with carbon -- or worse, has some melting -- and flow restricts accordingly. (Look after driving at night -- if your cat is glowing red, it needs replaced. Or you can take it off and hold it to light and see how much comes through...).

Magnaflow for instance puts priority on maximizing performance while meeting emissions requirements. Factory toyota probably put minimizing costs first, emissions second, and peformance third (whether a 4 or 6 cylinder pickup, our factory exhaust and air intake systems are restrictive...).

If looking for performance, I'd suggest looking at a high flow cat or test pipe (definitely cheaper)... It's on my to do, but haven't actually done mine yet. I have a 3vze and am going to do a mandrel bent 2.5 system with magnaflow cat as I'm in one of the TX county with required emissions until my truck reaches it's 25th birthday -- and while 2.25 seems to be the sweet spot for the 22re and 3vze (seeing as how all aftermarket systems are there), I'm going with 2.5 as eventually I either want to go diesel or 5vze and the 2.5 system will work until I decide to further customize, and the 2.5 doesn't seem to hurt 3vze performance (but might for 22re)...

edeslaur

Ok, 5HP. Still not going to be able to tell. :-)

RSR

Folks spend $800+ on aftermarket headers to get an extra 5hp on the 3vze. 1/4 of that cash for the same gains sounds like bargin. haha

And if the cat's toast, replacing could have much more than a 5hp effect.

lemonth68

Monday I went by the local exhaust shop and got the cat cut off and new 2.25" pipe welded in for $50. Truck has better throttle response and is running smooth. I was scared it would sound bad but actually sounds pretty good. May experiment with a Flowmaster 60 series later on but for now I'm happy. New combination switch is next on the list after brakes and rotors this weekend if I get the time. Thanks everyone for the help.

jyou9

You might get a little pep on low end, but you might lose top end. That's been my experience on other vehicles, anyway. I gutted the cat on an s10 that I had, and man did it open that lil 2.2 up! It also made all the little rice burnin Honda's wanna race me, cuz it did affect the sound. It did help my gas mileage a bit though, about 3 mpgs!

My question to anyone who has done this on their Toyota is more about mpgs. Gains? Loses? Toyotas aren't known for gas mileage once they're lifted, but my 87 is stock-ish, only running 30's. And for a carb'd engine, its pullin 20's in all city driving conditions, which ain't bad IMHO. If I can get better mpg's by snatchin the cat off, I'd say it'd be worth it!