exhaust question

[04xplorer]

Hello, i have a 04 4.6 explorer with a Flowmaster 40 on it already, i was considering removing the third catalytic converter for a louder sound, my only question was would i have to worry about it running to lean? I will be getting a programmer from henson performance, but not for a while. I wont be doing any towing or anything until it is tuned. Also, it has the stock air box.

Thoughts?

Thanks

 

[4dlover]

dont do it

it is illegal for one thing and it cleans the nasty gases your ex will spit out without it, and yes it will probably start throwing codes as soon as u take it off bad idea

 

[JDT]

Cutting the third cat is illegal, but there's no O2 sensors after it and it won't throw codes, I've done it and it won't run lean or anything, it gives it a lot more top end power, it's only good stuff. If where you live does emissions test and inspections, you might not pass, here in good ole KY we don't have any of that crap

 

[dwcopple]

I just got mine done last week. It DOES NOT throw a code. There are two other cats already so as far as nasty gasses, I would need proof of that one. Not a bad idea to ditch it at all. I've picked up .4 MPG so far this week and that is with no highway mileage. It is a win-win. No tune needed, you can unhook the negative battery cable overnight if you want to let the PCM re-learn next time you drive.

 

[04xplorer]

Thanks guys, my father and brother both have this done for years but they are running a programmer. we do not have any emissions so im not exactly concerned.

 

[dwcopple]

where in MI are you?

 

[04xplorer]

South of frankenmuth,

 

[Kazer]

let us know if it makes your exhaust noticeably louder without the third can

 

[AKbrener]

Mine only has 2 cats. but its an 05, i guess thats the difference?

 

[dwcopple]

yours has three. One on each manifold and the big one before the muffler.

 

[Kazer]

Actually, dwcopple, he's right. Some or maybe all 05s only have two cats

 

[AKbrener]

yours has three. One on each manifold and the big one before the muffler.

Have you flown to Houston and looked under my explorer without me knowing??

 

[dwcopple]

easy killer, my mistake. I was unaware of any change in the same generation of Ex...my fault.

 

[Black Dynomite]

My 05 has 3.