The boys bought an cat-less x-pipe for the wifey's 04, they want to try it on this weekend. What will happen to this ride that I need to prepare for regarding codes, performance, and sound through stock exhaust?

Can this be done without harm to the motor without a tuner?

 

Will need MIL eliminators otherwise the check engine light will come on.

Otherwise no issues. The rear O2's read the exhaust after the cats. If the readings dont fall within set parameters they set off the light and an emissions code. The MIL eliminators go in between the rear O2's and the harness that plugs into them. They trick the computer by sending back a signal that is within the correct parameters and the computer will be happy again.

Will cause no harm to the engine either way. Should free up 10 hp by removing the cats. The motor will thank you.

Hurst

 

Thanks Hurst.

MIL eliminators ... anywhere local?

 

you need mil eliminators (malfunction indicator light). these hook into the rear o2 sensors and fool the factory sensors. The front ones will still be fine. I think it is the best mod for these cars. almost 23 hp. don't buy mil lights used because they are prone to go bad sometimes. ebay around 60 bucks for a set. If you dont like the sound throw a set of used flowmaster 40's. gettin rid of the 4 cats will help wake this pup up.

 

im a slow typer but only 10 hp i thought 20 or so huh

 

On my Cobra I gained quite a substantial amount of HP with the Catless H-Pipe and 3" Exhaust. I don't remember the exact number, but I bet it was at least 20 hp, and the power curve got a lot better (thanks mainly to CBRTRX and James @ RR tuning via the Diablo Predator that I had)

 

15 - 20 with aftermarket mufflers and catback. Not with just a mid pipe swap. The stock 2.25" mufflers and pipe will choke it. A complete 2.5" exhaust with headers, mid pipe, mufflers and cat back is usually worth between 25 - 35 hp depending on the tune and accompanying mods.

Hurst

 

Look what I found ... MIL eliminators on the cheap!

>>> MIL/CEL Eliminator How-To

So then, no harm done removing cats. Gotta kill the code source - rear O2's.

Will sound louder, run a little differently and later when we get an aftermarket exhaust and visit Sam / Coastal for a tune ... wifey's ride will keep getting better, eh?

BTW Headers available ceramic coated? Any recommended product being used?
LMK guys.

 

There is a way to turn off the rear o2 sensors when you tune the computer for future knowledge. As for the headers are you looking for mid lengths, equal lenghts, or long tubes?

 

That which work with the x-pipe the boys bought to connect to OE exhaust, I presume.