Possible to eliminate the CATs and O2 sensors....?

[XpedientJ]

Time to replace the exhaust system in the '99, so.....since it's past age involving emissions inspection, I'm wondering it the ECU/brain will still keep the engine running without the cats or pre- and post-cat O2 sensors reporting in....

Wishful thinkin', I imagine, but don't recall it being discussed in the past, so thought it worth inquiring. ANY way to spoof the requisite inputs, etc...?? Perhaps, to leave the sensors but eliminate the cat, etc....

Thanks for any knowledgeable and experienced replies.

 

[jls095]

As I'm sure you know, it's illegal to remove emissions equipment that came from the factory on a vehicle. It's also against form policy to discuss doing so. You need the upstream 02 sensor - it provides vital inputs to your engine on air/fuel ratio. The downstream sensor merely tells your computer if you cat is working properly. Although MA does not do the emissions "sniffer" tailpipe test, inspectors do read the ECU. Without a cat, you will have a check engine light for low cat efficiency and you will fail. You stand little, if anything, to gain performance-wise by ditching the cat. "High-flow" replacements can be had for relatively cheap. Just be happy you don't have the California emissions package on some 2000/2001s with 3 cats and 4 O2 sensors...

 

[CarbonXJ]

As I'm sure you know, it's illegal to remove emissions equipment that came from the factory on a vehicle. It's also against form policy to discuss doing so.
^^^
Just be happy you don't have the California emissions package on some 2000/2001s with 3 cats and 4 O2 sensors...

You're much better off replacing the converter with a new "high performance" one - I had my system done from the header flange back with new stainless pipe, cat, and muffler for about $300. The cat was only $45 and welded into the system nicely.

I have the '00 Cali package and it is a PAIN The two mini cats on the manifold are just little ovens under the hood...

 

[blondejoncherokee]

No. don't remove the Cat and o2 sensors.

 

[anthrax323]

You're much better off replacing the converter with a new "high performance" one - I had my system done from the header flange back with new stainless pipe, cat, and muffler for about $300. The cat was only $45 and welded into the system nicely.

I have the '00 Cali package and it is a PAIN The two mini cats on the manifold are just little ovens under the hood...

Remember: the 2000 models still had the Federal emissions offering, which has its own ECU... And both Federal and California emissions models share the same bank 1 upstream/downstream sensor wiring (they're just longer in the Federal models to reach further downstream than the manifold).

It even plugs straight into a 2001! That's all I can really say.

 

[cal]

Time to replace the exhaust system in the '99, so.....since it's past age involving emissions inspection, I'm wondering it the ECU/brain will still keep the engine running without the cats or pre- and post-cat O2 sensors reporting in....

Wishful thinkin', I imagine, but don't recall it being discussed in the past, so thought it worth inquiring. ANY way to spoof the requisite inputs, etc...?? Perhaps, to leave the sensors but eliminate the cat, etc....

Thanks for any knowledgeable and experienced replies.

As pointed out, this is a federal offense.

Also I believe its against the forum rules to even promote doing it (but i'm not going digging to verify).

 

[GSequoia]

Not to mention why would you remove the O2 sensors? Is it because you enjoy the thought of tanking your fuel economy?

 

[RoyalXJ]

I kept destroying cats so I now have a hollow shell. Both of sensors are in place and work just fine.

 

[Anak]

You really do want that first O2 sensor. I suppose there are going to be fewer and fewer folks who remember the challenges associated with altitude change on old school carbureted vehicles, but I certainly recall them. I suppose things are a bit flatter back east, but I suspect there are still some substantial benefits to that feedback for the fuel and timing adjustments which the computer now handles so much more efficiently.

As to the second one, you might be able to do some research on your own for that. The word dummy might come into play.