I Have a ZZP 2.5" DP w/ a High-Flow Cat & a Custom Mandrel Bend "cat-back" exhaust.
But I Want a Little More Sound, and i was Told That Removing My Cat Would do so and ADD Some Ponys as well.

Is This Info Correct?
Would I Have To Mod Anything to "Delete" my Cat??
any o2 sensor changes?

 

You will more than likely start throwing codes if you remove the cat. Not to mention, it is not smog legal in MANY states, so it could screw you for inspections/ smog checks.

If you already have a high flow cat, I doubt you will gain much in terms of power from completely deleting it. (a little sure, but I doubt you'd feel it).

 

It will give you a very little bit more sound- but its not a drastic change by any means. You can definitely hear it right away in an A/B comparison, but after a week or so, you won't even realize it anymore.

What is the rest of your exhaust comprised of? If you want a noticeable change, maybe you should think about changing mufflers?

Since you already have an aftermarket downpipe, very free flowing catback, and a high flow cat- your power gain is going to be practically zip, your exhaust behind the manifolds just isn't that restrictive anymore because 95% of your mods are exhaust mods. If you want more power- focus in another area, some ER rockers, an HV3, a plog, a tuned pcm- something else.

Yes- deleting your cat completely will make the rear O2 sensor throw a code (since it thinks your cat is leaking uncleaned air through). You have two options- 1 is to get an O2 emulator to put in place of the rear O2, tells the pcm that the cat is always working fine, even though it doesn't exist. Option 2 is to get a tuned pcm and have the code turned off (which would also give you the benefit of getting a tuned pcm at the same time, so better fueling, better shifting, etc)- they only run like $100.

Yeah, thats what I'd be most worried about- I always thought Cali was the worst state for emission laws.

However, as long as they don't do a visual check- with either the emulator or the pcm with the code turned off- you will pass the obd2 computer plug in test.

If they do a visual you could get the 'allflow' cat from frozen boost (google it if you want to see it)- it is a cat's external body with a piece of straight tubing inside so you can pass the visual tests also. But they're like $40, and as was said before, you aren't really going to gain any real power from it.

 

I ment illegal...my bad!

Not having a cat is ILLEGAL in MANY states. And yes, California is one of the hardest states for passing smog.

 

He has a friend who will "pass" him.

I spoke to him about this on AIM earlier. He is still running his stock mufflers, told him to swap those out before deleting his cat for sounds. Downpipe + High-flow is sufficient. The only reason you WOULDN'T get the cat is to save some money that you already spent.

 

Definitely- the muffler accounts to probably 80-90% of your volume reduction.

 

Hey, i dont much experience with pcm's but would i have to get another pcm if i want a tuned one or how do you go about upgrading from stock to tuned pcm?

 

You can order one through a Vendor, such as ZZP or Intense. They will send you a PCM that is already "tuned" and you would plug it into your car. Then you would take your stock PCM and return it to them as a Core.

 

ur the man. Thanks! Im trying to get started here u know. but time is not letting me.

 

i noticed a HUGE difference when i had my cat and ubend delete. its been a little bit more than 2 weeks now and i still notice it.
i have recently installed a downpipe from ZZP and again there was a nice difference.