Cutting the 2nd cat off?

So yesterday I brough my ranger to the exhaust shop, and had 'em put on Flowmaster 40. The cut the old mufler off, and started it for me and reved it up so I could hear what it sounded like. Straights it was to poppy. Then they held a glasspack on it, a diferent Flowmaster, than the 40. The 40 had a rumble to it, and sounded the best. But after they welded it back up to the tail pipe, it's not even loud. I can't hear ir in the cab drivin'. Does it need some time to break in to sound good. So I think I heard one time the 2nd cat is usless, and restricts power. Well, my buddy has a lift, tig welder, so many tools cuz his dad is a mechanic, we're gonna use a sawsall to sut off the 2nd cat, weld a cupler to spice the pipes back together. Here in CO you have to have emmision were I live it sucks, but I just got 'em done yeserday, and past alright, so I don't hafta worry about them for another 2 years, and in 2 years I'll probably move in the counthy next to me that doesn't make you have emisions. So my question is:

Will it make it sound better and better flow?

Will it mess with the computer and all that taking it off?

Will it fail emmisions taking off the 2nd cat?

Will it run better?

Will it make it sound better and better flow?

Sound is personal opinion, it won't flow much better.

Will it mess with the computer and all that taking it off?

If there is an 02 senser behind it yes, if not probably not.

Will it fail emmisions taking off the 2nd cat?

More than likely.

Will it run better?

If it does there was a problem with a cat, which you would probably notice.


Give your flowmaster more time, mufflers need a couple hundred miles to break in.

It's a 1993, so no downstream HEGO sensor.

But you ARE tampering with an emissions device and it will be noticed during an inspection if the inspector looks under the truck. Some state inspections include that.

It will also screw up tailpipe emissions. The second cat is VERY DIFFERENT from the first, and you will have no oxidation catalysis. That means whatever HC and CO you make gets spit out the tailpipe with no conversion. At least you'll clean up the NOx, but this is going to be a VERY dirty truck.

85_Ranger4x4 said:

Will it make it sound better and better flow?

Sound is personal opinion, it won't flow much better.

Will it mess with the computer and all that taking it off?

If there is an 02 senser behind it yes, if not probably not.

Will it fail emmisions taking off the 2nd cat?

More than likely.

Will it run better?

If it does there was a problem with a cat, which you would probably notice.


Give your flowmaster more time, mufflers need a couple hundred miles to break in.

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How exactly does a flowmaster "break in"? Theres no packing inside the "plug up" with soot.

If you want the rumble back remove your tail pipe, its the only way to get the true rumble (although after a while it will rattle the fillings out of your head, I had mine like hat for a little while until I couldn't take it any more), as soon as you run any pipe off of it even with no cats it will not physically rumble the truck anymore. You could remove both cats and run a single universal cat like I did (mine passed with flying colors). Also a before tire exit will be louder. You can hear my exhaust in the link below. It's a flowmaster 40 will 2 1/2" pipe from the y-pipe back (no cat right now) and a 3" tip exiting before the rear tire.
http://youtube.com/watch?v=1mFgxBSVxT4
At about 4 mins into this video you can hear mine from the inside, I think it sounds quite good for a v6. Als the bigging of the video showcases the difference between a locker (my rig) and an LS (my buddies XJ).
http://youtube.com/watch?v=bq4ENOJDUO8

Mufflers do change as they wear in no matter what is in them. Straightpipes even get louder with a little age to them.

I think what it needs to sound good is get rid of the 2 cats?

Damn, your BII is kick ass. Is that Cherokee limited slip or open? That video just proves how much a locker helps. How does it drive on the street with the locked rear end?

Also about the exhaust I'm kinda pissed I spent $200 and it don't sound good. The shop uped the price of the flowmaster to $130 where they cost $90 at Pep Boys. I think what I gotta do is get a good cat, and have it 2.5'' from the y pipe back, and run the pipe out right before the rear wheel. Sound good? Or just run no cats, but in 2 years when I get emisions, I'll hafta put the cats back on, so I would use u blots and cuplers instead of weld it on, for easy taking off and putting on. If I didn't need emisions, I would weld it up. If I still live where I do in 2 years. If I move where I don't need emisions the cats will be off for good.

King Crush said:

Damn, your BII is kick ass. Is that Cherokee limited slip or open? That video just proves how much a locker helps. How does it drive on the street with the locked rear end?

Also about the exhaust I'm kinda pissed I spent $200 and it don't sound good. The shop uped the price of the flowmaster to $130 where they cost $90 at Pep Boys. I think what I gotta do is get a good cat, and have it 2.5'' from the y pipe back, and run the pipe out right before the rear wheel. Sound good? Or just run no cats, but in 2 years when I get emisions, I'll hafta put the cats back on, so I would use u blots and cuplers instead of weld it on, for easy taking off and putting on. If I didn't need emisions, I would weld it up. If I still live where I do in 2 years. If I move where I don't need emisions the cats will be off for good.

Click to expand...

The XJ has an L/S in the rear, doesn't help much off-road... It drives pretty damn well, of course it will never be as smooth as "standard" rearend but it really supprised me on how smooth it is as long as you pay attention when you drive it and apply the throttle correctly, which isnt very hard.

I went through many exhaust setups until I found this one, and I like it, but beware it is really damn loud! My buddy was cruising next to me in his rig with his window down on a freeway grade and I was runnin abou 65MPH at around 2800-2900RPM and he said it was almost deafening to drive next to... I really think if I added a turndown tip it would be much, much quieter.

Hahnsb2 said:

The XJ has an L/S in the rear, doesn't help much off-road... It drives pretty damn well, of course it will never be as smooth as "standard" rearend but it really supprised me on how smooth it is as long as you pay attention when you drive it and apply the throttle correctly, which isnt very hard.

I went through many exhaust setups until I found this one, and I like it, but beware it is really damn loud! My buddy was cruising next to me in his rig with his window down on a freeway grade and I was runnin abou 65MPH at around 2800-2900RPM and he said it was almost deafening to drive next to... I really think if I added a turndown tip it would be much, much quieter.

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My first truck when I was 16 was a 64 f-100 I bought from t he neighbor. It had a 292 in it. It had true dual exhaust with glass packs that were rusted out, so they didn't do much. I cut the class pack off, so it was open right under the cab. Now that was load. I drove it like that for 6 months, than I just ran piped out the side straight pipe cuz it was so load in the cab. There is no such thing as too loud as long as it isn't a ricer loud.

Ok this may sound ridiculous, but while cruising it's LOUDER than my buddy's 76 ford f250 with a straightpiped 460 (the pipe ends under the passenger seat) and it's almost as loud under acceleration...

mine is a 2000 truck came from factory with 2 cats took one off still passes emisions test i was told as long as you have one your ok

What I don't understand is why everybody thinks a cat kills performance. They don't kill "flow" or any other BS like that, given that they are operating properly. They don't even kill sound. I ran my 2.5 for 3 years with a straight pipe after the 2nd cat and it sounded like I expected it to...a sick tractor. When there was a problem with the first cat, I replaced all of what was left of the exhaust system. When we were messing with it during the exhaust repalcement, guess what it sounded like without any cat?....A sick tractor...exactly the same!!!

As to power, of course mine would have less without the cats....there is a O2 sensor after the cats on mine.

Simple_serf said:

They don't even kill sound.

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When running a muffler, yes they do. After putting a cat on mine to pass emissions, the sound lost all its "balls", just an annoying hi-pitched sound instead of a low deep rumble like before and that's the reason it's no longer there and is sitting on the floor in my shop. On a EFI V8 (Old carbed V8s pass no problem without cats), I wouldn't pull the cats because it's a V8 and will sound good no matter what. I've been through probably 10 different exhaust setups on my rig, with a full tailpipe it sounded best with a cat and with my before tire exit it sounds better without one, just my personal observations. And yes even if you don't have emissions testing it IS illegal to remove it. And yes there will be no power increase.

i second that, i have a 40 and when i put it on it doesnt have that much of a grumble as yours does with the cats off, thats with no downpipe too. i have the first cat and the second one has a bunch of holes through it, dont know if it really helped though. what i did now was took off the 40 and just put a down pipe after the cat, sounds similar to your setup but i dont think its as loud.

i was wondering how you fit a new pipe on where its got an oval shape before the first cat?

mikhail said:

i second that, i have a 40 and when i put it on it doesnt have that much of a grumble as yours does with the cats off, thats with no downpipe too. i have the first cat and the second one has a bunch of holes through it, dont know if it really helped though. what i did now was took off the 40 and just put a down pipe after the cat, sounds similar to your setup but i dont think its as loud.

i was wondering how you fit a new pipe on where its got an oval shape before the first cat?

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Mine already had a pipe welded to the flange and a standard cat attached to that when I got it. It appears the just ovaled a piece of 2 1/2" pipe with some heat and welded it to the flange.