I am looking for everyones thoughts on my idea for my exhaust..

i want to gut my post sensor cat so my 2nd cat or well my 4th cat i guess you could also say. ha.. i want to gut the cat and straight pipe it with no muffler. Does anyone know the gains it will give?

I live in an emission free county so im not so worried about the legalities.

Also my next thought was to gut the cat and run straight pipe into a flowmaster super 40 or super 44.. what does everyone think about this?

Any thoughts or ideas would be greatly appreciated in my quest for sound and performance.

 

On my old 2.9 it ran the exhaust manifold to a y pipe the 2 cats, and I left about 3 ft of piping and chopped it right before the muffler. I ran it open with only the cats to muffle it. sounded great to me. below 3k rpms it had a nice low grumble never had a problem with cops, but if you went WOT everyone heard that truck coming

 

Its gonna drone really really bad, it sounds awesome at idle though.

 

Alright yeah i have those 2 cats right after the exhaust manifolds and then that O2 sensor between numbers 3 and 4 and i was thinking just to remove number 4 so i dont throw a code and then straight pipe it out past my bed so i dont get exhaust in the cab.. also anyone know the performance yields to this?

 

man dont do it, just weld a cut off before your muffler and keep it open all the time, about the same

 

um the 2 main sensors are before all the cats... im pretty sure.

dont gut them, it will sound and run like crap, and no gain.

flowmasters suck, but im about the only one that thinks that on this site.

think about this, your going to gut your cats for more flow but then putting in a restrictive muffler???? doesnt make sense. magnaflow and borla are wide open designs.

 

You are required to keep the cats, they are there for a reason. Besides it will sound hollow. Think about it, you have 2" pipe going all the way into those 4 or 5" empty cats, then back into 2" pipe again.. It would seem its going to cause a bottleneck in the exhaust and hurt performance. To me it would seem pointless. But to each their own. I say get some magnaflow hi-flow converters and swap them in, keep it legal, good performance with sound/flow. Just my .02 .

 

SO that one thats in between cats 3 and 4 (o2 sensor) doesnt matter? and what did you use for your cats??

and well i will look into borla and magnaflow everyone just refers me to flowmaster for sound.

i like your exhaust setup and wish to know what you did after you cats on your exhaust?? and you just put the two sensors that were right after the headers back in roughly the same spot?

 

there are only 3 o2 sensors in my 03, the front two are the most important. the back one most of the time is shut off in a tuned environment. the last one just needs to be before the muffler to keep from getting a check engine light.

 

Yeah the only reason I'm going with Flowmaster is for the sound, I really don't care about performance with my engine.

 

If you want loud, then run a cherry bom extreme muffler. They are similiar to the flowmaster 10 series.

 

I have a straight piped exhaust and it is loud. At idle it sounds amazing, at highway speeds it does drone pretty bad.

 

to get rid of the drone you need to move it back past the cab

 

I have mine out the back in to duals. It still drones pretty bad.

 

Zach, could you explain what you meant by the 3rd is usually shut off in a tuned environment? like as in it is manually shut off? or it just automatically shut offs by the trucks own doing??

 

no if you buy a tuner, from bamachips or rogue performance they i think shut those off on purpose.

also i answered a bunch of your questions in your other exhaust thread.

 

really, i figured it would quiet down some

 

yeah i saw. and okay then i will look into the chip to go along with it.. now did you do your own motor drop for your jba headers??

 

What county do you live in?

 

you can do the headers right though the fenderwell. everyone does it that way. you will need like ratchet wrenches which help a lot. other than that its like a days job for the weekend warrior.

 

oh so i just remove tire and suspension and kinda wiggle em in there?? what would be the basic instructions for doing it yourself?

 

they come with the headers. but you remove the tire, then remove the inner fender, no suspension moving/changes

its tight but not that bad.

 

I drove mine around without the muffler on for a few minutes...put my Bassani on, and it might as well have no muffler, Bassani's muffler did nothing to quite the thing...If that helps your decision.

 

so i dont have to remove the acutally out fender at all?

 

i run mine just with cats. no muffler and it drones big time. whatever you do....run it all the way back. if you lop it off near the cab you will regret it. and i agree with zach...the cats are there for a reason. your engine need the backpressure. why give them the boot then put in a flowmaster? not understanding that concept.