Just put my Borla on today and I have some ??

[4Wheelin]

I had my Borla muffler put on today and had them custom fab a pipe out the back with a single tip and I love the way it sounds but I was curious does this offer me any more horsepower or any better gas mileage?

 

[yob_yeknom]

yes

The Borla muffler offers less restriction than the stock muffler which will allow the engine to 'exhale' easier. This gives you more horsepower and better gas mileage.

 

[espnfreak]

get some headers or a high flow cat and you'll have a much better exhaust system which will be able to breathe easier and sound great!

 

[leenjen]

it's been a while since i was under my X. are there 2 cats??

if so, do you need both, or can you bypass one? is it legal?

 

[espnfreak]

i believe there's only 1

 

[yob_yeknom]

I'm not sure if there are one or two cats under your Explorer, but it would be illegal to bypass one of them.

 

[4Wheelin]

There is one cat and one resonator. I am pretty sure you can take the resonator off and be ok but you have to have a cat.

 

[yob_yeknom]

Isn't the stock resonator located after the muffler? If so, you got rid of it when you had the new pipe put on.

 

[4Wheelin]

On the early models if you climb under there and look the cat is first and then comes the resonator (its either that or the other way around). That is also why they sell cat back systems with just mufflers pipes and tips.

 

[dirt,rust&tears]

I don't know about newer models, but on my '91, it goes cat-resonator-muffler. You can remove the resonator without any problems. Obviously it is illegal to bypass/remove the cat. When my stock exhuast finally lost its battle with Michigan winters,
I didn't have the muffler shop replace the resonator. It made the vehicle only slightly louder. It may have improved flow slighty, but not enough to notice. I did it mostly because it saved me over $100 to not replace it.

 

[espnfreak]

its also illegal to run a car without a converter for emissions reasons and pollution overseas they didnt have any rules about converters, but converters make your car burn gas more efficiently

 

[Josh]

CATs

There are 2 CATs under my 91 XLT and the resonator is in the tailpipe above the axal. I just went to Midas and had the resonator removed and a new Raven performance muffler put on. Most places won't touch your CATs unless they are bad. I didn't even see the resonator until the guy pointed it to me. It looks like a mini cherry bomb muffler if you have ever seen one.

 

[Big Poppa]

Would no cat help or hurt performance? It would flow better, but is there any special need for it besides emissions? Would the sensors for emissions get thrown off w/out it?
Thanks

 

[leenjen]

Originally posted by Big Poppa
Would no cat help or hurt performance

on most newer cars it will hurt the performance by taking the cat off, they are designed to one. on older cars people have been known to bypass the cat (which is illegal) to get a slight gain, but not much. a hi-flow cat will be the best thing for your explorer

 

[leenjen]

....

Big Poppa, i didn't know Ford made 2 door EB Exoplorers. yours is the first one i heard of.

 

[yob_yeknom]

Re: CATs

Originally posted by Josh
There are 2 CATs under my 91 XLT and the resonator is in the tailpipe above the axal

That's what I thought.

Originally posted by Big Poppa
Would no cat help or hurt performance

It would hurt it, especially on models with a O2 sensor after the cat.

 

[ACBlessing]

On my 2000 X, there are 4 cats but they're hi flow, then it goes to 2 pipes in to the muffler and one pipe into the resonator (silencer) and on to the tip.

Problem is, it keeps getting necked down from the cats back...

You'll definitely want a cat-back system for this model.

-AC