Questions about doing a cat delete

[Projecttahoe]

I went ahead and replaced all 4 02 sensors, and I'm fairly certain the cats are toast, strong exhaust smell and still throwing p0420. So my question is has anyone here done a cat delete and seen positive performance results or is it better to just replace the cats, (also no inspections in my state)

 

[gooffeyguy]

I'm sure you will see a slight performance increase, along with a large sound increase. Don't forget when doing this you will need to have your rear O2 sensors turned off with a tune, or use something to fool it like MIL eliminators (resistor pack) or I've heard of people having success with spark plug non-foulers

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics, please.

I cannot help you with your specific question, but other knowledgeable folks will chime in.

 

[iamdub]

I don't think the gain in performance, if any, is worth the excessive noise and smell. If you're complaining about the strong exhaust smell now, wait 'til you have no filter on your exhaust at all. You won't be able to drive with the windows down (idling or moving) or YOU will smell like an old cat converter. It sticks in your clothes.

 

[Rocket Man]

Agreed^^^. Plus you won’t find an exhaust shop to delete the cats, they won’t touch it so you’d have to do the work yourself plus like Chris said you’ll have to find a tuner to delete the cats in the ecm or you’ll have a constant check engine light and you’ll have to sign an affidavit stating the truck will only be driven off road. Nobody wants the liability of deleting an emission control device. It can be done but unless you really want a loud obnoxious truck it’s not a great idea.

 

[swathdiver]

I went ahead and replaced all 4 02 sensors, and I'm fairly certain the cats are toast, strong exhaust smell and still throwing p0420. So my question is has anyone here done a cat delete and seen positive performance results or is it better to just replace the cats, (also no inspections in my state)

I tried to go this route but the entire industry is set against it and so I just got new cats and y-pipe. Nobody is allowed to sell a catless Y-pipe for a non antique or else the G-men will come knocking at their door. Wusses.

Plus, your car won't stink and will still be quiet, remember, the cats are right on the firewall!

 

[Rocket Man]

I tried to go this route but the entire industry is set against it and so I just got new cats and y-pipe. Nobody is allowed to sell a catless Y-pipe for a non antique or else the G-men will come knocking at their door. Wusses.

Plus, your car won't stink and will still be quiet, remember, the cats are right on the firewall!

Actually you can still buy catless systems from American Racing Headers, at least according to their website. I saw Stainless Works no longer sells catless systems. I guess the EPA has left ARH alone for now.

 

[swathdiver]

Actually you can still buy catless systems from American Racing Headers, at least according to their website. I saw Stainless Works no longer sells catless systems. I guess the EPA has left ARH alone for now.

Correct, I should have added the caveat that nobody made them for stock manifolds (GMT800 and GMT900), only headers.

 

[Projecttahoe]

Hey guys i appreciate all the replies and it definitely sounds like the cons outweigh the pros here , and even the cost makes it seem not worth doing with the sensor resistors and an almost mandatory tune and possibly future engine issues by not having the cats back pressure. Now the trick is finding some cheap cats lol

 

[drakon543]

you definitely wont see enough noticeable gains to out weight the extra effort to completely remove them. one thing you can do is spend a few extra bucks when you replace the cats and get something from a more performance related company. still won't be any real gains besides cats that flow vs partially plugged cats. however ive always noticed they don't seem to hinder the sound quite so much.