Hello all! Hope everyone has been doing well and staying healthy. I have a couple of questions regarding gutting my pre cats. I’ve done my research and still feel a little empty handed as my mind loves to over-think everything. I’ve been debating getting OBX headers or gutting the cats, and i’m going to go ahead and gut the cats first. Headers can wait a while(spending money is low.) I’m well aware of having to get an o2 sim for the SES, however, with the intake i’m running, i’m pretty sure the SES isn’t going anywhere anytime soon, and i'm fine with that(i'll just tape the light lol) My question is, will I have any issues by doing this mod? Issues meaning reliability problems, or anything that could compromise the health of my engine. I just passed 200k and ever since I bought the car at 182, i've maintained it immaculately and taken care of it like my child. Also, do I need to get any sort of tune done to it if I go through with this? I have the cat thats in front of the resonator gutted already and the car seems to definitely have a richer exhaust scent. If there is anything else anyone knows and would like to chime in on, feel free! Im also not set in stone on doing this, just want some cheap power, so if you want to convince me to not do so, have at it! Thanks in advance and take care!!

 

just putting a piece of tape over the light is an easy fix and gutting everything out will no doubt give you a little bit extra power from the car breathing easier. Your biggest issue is when inspection time comes, how much you will need to spend or need to undo to get the car to pass

 

I definitely feel that, I just got it through inspection, and hopefully by the time two years elapses, I should have spending money to be able to do what needs to be done. Have you done the mod yourself?

 

You didn't mention what engine. 3.5 has to be gutted/deleted.

 

3.0, sadly

 

3.0s only has 1 precat in the front. What you could is remove front header with precat. And swap over to a 4th gen front header and get you a wsp y pipe for a 4th gen and add the 2 02 bungs and be set. But if you want to skip the wsp y pipe you could add piping with flange to extend to the front off the 4th gen header to fit and just add the 1 02 sensor.

 

Interesting. Ill have to look into that and do some more research. Thanks!

 

Installing o2 spacers on the downstream o2 sensors will stop the SES light and they are easier/cheaper to use. It just pulls the sensor a bit further away from the flow to report less. I have them for years now with no issue.

 

The stock ecu should be more than sufficient to handle hollowed out cats. If you using super unleaded 92-93 octane, you can probably bump up your timing by a degree or two if its not already done, for a bit more power. As long as you are not living in a strict emission inspection state, the o2 spacers on your two downstream sensors will prevent a ses light from coming on for those codes, if you have other codes then that's another issue. Spacers, I have them on for a few years, only issue I have with the o2 spacers is that my catalyst monitor is always not ready, it hasn't been ready ever since the spacers went in but never had a converter efficiency code since. Luckily in MOST states, one not ready emission monitor is allow to pass..................In my area, depending on year of vehicle, one or two monitors can be not ready to pass. .As long as you can legally pass inspection in your area it shouldn't be a problem, you don't want to hollow out perfectly good cats and run into not ever able to pass inspection again or having to spend more than the car is worth trying to get it back up to compliance.

 

Where did you get your spacers if you dont mind me asking?

 

I havent upped my timing yet, I should look into it though. I was also thinking of finding an exhaust shop that will take out the old cats and weld in regular exhaust pipe in trade for the good cats

 

It's been years so I can't locate the site but you can find them on ebay and other sites these days.

 

Cool thanks