I was doing an oil change yesterday and noticed that there are no rear O2 sensors on LS, which is great considering removing cats wont give out a cel or anything, so i ve been thinking about Joez axle back and removing the cats, anyone did it?
What are pros /cons of doing this?
removing cats alone is usually good for like 10 whp on a v8, plus the exhaust should be a great upgrade...

 

Pros - None really. I seriously doubt you will get another 10 bhp from reduced back pressure (tests usually show a gain of about 1 bhp and 1 lb-ft of torque), but even if you do get half that, unless you are drag racing at a sanctioned strip, the difference will be imperceptible.

Cons - It is illegal.

If your state has emissions inspections it will fail.

And from a strictly moral/environmental perspective, it is just plain wrong.

 

yeah and the pro's against it aint worth it, test pipes might be an option but I haven't looked under there in a bit so I am unfamiliar..

 

Hmmm I never checked for that! I did notice there are also Hydrocarbon Filters on our air box lids that most us 4Runner guys get rid of right away. I have had decent gains on my cars in the past that I have removed my converters. I am positive it will be more than a couple HP. Environmental impact? There are plenty of Diesel guys that do a lot worse.. I was thinking about putting an x-section in my exhaust and maybe ditching the resonators to see how it would sound. Maybe someday.

 

imho its just not that type of car bro. I would stick with the exhaust and leave the cats alone

 

would be interesting to see someone actually do this.

 

I actually went and asked around a lot to do something like this. The guys over at the IS-F forums are famous for taking out their secondary cats for some extra power. I'm not sure if the LS has secondaries like the IS-F but I am sure that the primaries have a sensor on them and I am sure that taking them off will have a negative effect on the way the engine runs. I would definitely not take out the primaries, but if there are 2nd's on our cars it might be good for just a little bump. IMO it's not worth the trouble.

 

I wouldn't chop up a $2k system

 

As long as there are no O2 sensors after catalytic converters its a 500$ max exhaust system at any exhaust shop.

FYI LS exhaust is setup is nice and simple one: headers-o2 sensors-cats-resonators-mufflers- which means you can do anything pretty much anything after o2 sensors.
I have two brand new 2.5 inch high-flow cats in my basement which i never put on my old car , its giving me ideas....

 

Straight pipes headers back FTW!! LMAO or maybe some side exit exhaust?