Cats ?
 

when I look under my 2004 mustang gt it looks like there are 4 different cats?
I was thinking into some slp cats but I am confused on how many cats I have.
And is there a horsepower gain to this?
Thanks.

/

i honestly dont know how many cats there are, because i dont own a mustang, however i can tell you that i believe they do have four cats. two right after the exhaust manifolds (one each side) and further down, there should be another two right before the resonator on each side.

someone correct me if i am wrong, however that is how my truck works.

and yes, slp catss will give you a nice gain in power. it allows better flow, which causes less backpressure from the motor.

its weird how it works, but im sure if im wrong someone will correct me.

good luck

Sorry, no resonators. And yes, on your 04, there are 4.

when i got my car it had two cats on it, but i had an aftermarket x pipe
you want to take them off if your looking to gain horsepower,

but some state you need to pass emissions so you might need to keep at least two of them on

What do you mean by slp cats? Are you talking about the race pipes?

There are two preheaters and two cats (the rears).

thanks so much, are these pre-heaters restrictive like cats ?

There are 4 cats, period. The front ones are used when the engine has just started since cats needs heat to work, hence why they are so close to the manifolds. The rears on the other hand take over after everything warmed up.