taking 1 of the 2 cats off the exhaust.

[bnichols04]

I have a 93 explorer and I have dual exhaust on it right now. It sounds decient but I want it to sound louder. I was just looking under the truck and I saw that the muffler shope had just put a new exhause system from the cats back. I was thinking that takeing one of the 2 cats off would give me the louder sound that I was looking for. Should I do this or is it a bad idea. I am open to suggestions!

 

[DannyDynamite]

One is a resenator and ones a cat...try taking the resenator off....just make some kind of test pipe to put in its spot...i had a test pipe on my old ford probe and it made me lose low end power but in higher rpms u could feel it, plus it made it louder..hope that helps later

 

[DannyDynamite]

u also better check out if the explorer has some kind of o2 sensor...cuz im not sure

 

[huskyfan23]

The o2 sensors are on the y-pipe, so nothing to worry about there.

 

[Alec]

No, they are both cats.

Either leave both factory cats on, or cut them both off for a single aftermarket unit.

The exhaust guru has spoken.

 

[bnichols04]

they both look the same. One is under that support bar and the other is not. I think they both are cats. If not which one is a resinator and which one is a cat. Which one should I take off??? Cat? I herd if you take the cat off that the check engine light would always be on. I think that I should take off the cat but I don't know. I want to make it a little louder but not hurting the engine. If I take either off will it hurt the engine???

 

[huskyfan23]

They are both cats. Taking them off will lower your backpressure tremendously, so you will lose lots of torque. It will make it a lot louder and since this is a first gen, won't get a check-engine light, because your oxygen sensors are in the y-pipe.

 

[Brandons]

2 cats on mine too, now that you say id lose torque, ill keep them

 

[Alec]

(not to mention it's illegal and irresponsible)

 

[Brandons]

hehe its not illegal here, just as long as it still passes the Etest

 

[bnichols04]

is there anything else I can do to the exhaust to make it growl a little more without having to get a new muffler??????? I thought takeing one of the cats would help the engine "breathe" better. That is the whold point of the new exhaust right???????? So thakeing one of the cats off would cose less restriction???

 

[huskyfan23]

Yes .. but less restriction means less torque. Taking the cats off will lower the torque a huge amount. I think it's like 30lb. Headers also help the engine breathe better.

 

[Maniak]

Replacing the 2 cats with 1 high flow cat isn't necessarily illegal or a bad idea.

Our '92 had 2 cats, and when I went to exhaust shops, not one of them recomended replacing the 2 with 2. There is only o2 sensors in front of the cats. As long as the new cat is efficient enough (which a new high flow should be) there won't be a problem UNLESS your state inspections say you can't replace 2 cats with 1. I know there are places like that (Ca for example)...

Here in Arizona (even in the Phoenix metro area) they don't care as long as the new cat works well enough to allow you to pass emisions (they use the 5 gas test up in Phx)...

In our case, the truck emisions improved greatly by replacing cats with over 200k miles on them with a new high flow cat.

The resonator is actually after the muffler. You can take out the resonator if you just want more sound.. Changing the cat won't really change the sound much if you don't change anything else.

From the pic, I am assuming you have a single y pipe with 2 cats that then goes into dual exhaust after the cat. If that isn't what you have and you are thinking of removing the cat from 1 bank (so there are no cats on one bank), then that would be bad,illegal,etc...

~Mark

 

[mhn3773]

in CA u also cant replace a working cat..so u have to slam a rock into it =)..woops

 

[Alec]

I didn't mean that installing a high-flow is illegal, just running without.

 

[mhn3773]

i dont think hes gunna listin to u alec...not what he wants to hear u told him just what was what and in the next post he keeped going like u had not said anything..lol

 

[MustangShane]

Ok bnichols here in Michigan we dont have to pass emissions testing. Which you should know. And its a waste of State money anyways. By cutting off the cats you're allowing your engine to breath better. Giving it more torque, just at a higher RPM. You are making the engine more efficent so duhhh , its going to have more power. Or else top fuel dragsters would run ten cats to have enough torque to tear apart the quarter mile! But they dont because flow = power. Your engine is just a big air pump. The more you can suck in and flow out the more power you can make. Now an easier way is to just hollow out the cats, then you dont have to search for a test pipe. If you need help just PM me and I'll see what I can do.

 

[huskyfan23]

You barely gain any horsepower and will lose lots of low-end torque. I don't believe you'll gain much, if any, in a higher RPM.

 

[MustangShane]

Trust me it's a noticable gain and enough to warrant the mod., especially if you plan on doing further mods to the motor. Everything builds on everthing else. So this "little" bit here and that "little" bit there add up to alot. Put a truck on a dyno and prove me wrong. I'm not saying it'll be 30 or more hp & torque. But at least 10 to 15 lb. ft. of torque and about 20 more miles per tank.

 

[Rick]

I have a '93 that came with 2 cats. I had them remvoed and installed a single hi-flow cat. There was more of a seat of the pants difference doing that mod then there was doing the cat back exhaust. Plus the exhaust note is excellent. Phoenix, AZ has VERY stringent exhaust testing. We use the same techniques and equipment as Calfornia. I have passed with a single cat every time.