I've got an '04 5.7 Durango, and one of the o2 sensors has gone bad. I'd like to just take the cats out, as it is nearing 100k miles, and I don't want to have to deal with clogged cats later one, and to remove the 02 sensors or trick them into making the engine run correctly? Does anyone know how to go about it?

And in case there's any emissions police or cry babies, this durango is for off road only.

 

you dont gain anything by doing it and in most cases taking off the cat will mess with the way that the truck runs, if its for off-road use only then i dont see why you would care about having the cel on anyway.

also is it one of the post-cat 02 sensors??

 

Well, there's two things to gain. Actually 3.

1st: Peace of mind knowing my higher mileage durango isn't going to have a clogged cat.

2nd: You do gain a bit of power.

3rd: No longer need to burn 89+ octane fuel, since the majority of newer normally aspirated cars, commonly called ULEV's (ultra low emission vehicle) require higher octane for the catalytic converters they use.

Yes it's the rear sensor. I've read a few places of guys just plugging the o2 sensor bung, and tying the sensor to the frame rail, but I've never seen any posts confirming that this worked.

 

that worked on my 98 dakota for a while, (we had to order a new sensor and cat, but this truck had 200k miles on it at that time) but idk if it would still work on the newer trucks

and i would like to see proof that taking the cat off gains you power, so please if you feel that you are correct, then prove it. i have seen exactly 0 evidence of any power gains and i have also never seen a cat clog except when the engine was running badly (my 98 had a bad plenum so was burning oil and there were no clogged cat symptoms, however the sniffers said it wasnt working)

 

You say "that worked for a while", did it stop working?

As for proof, a quick google search gave me this article which was for a little 4 banger civic with a cat back exhaust, then replaced the cat with a test pipe and gained 5 hp. I can only imagine the difference on the Hemi would be significantly more.

 

Forgot to post the link to the article... http://www.importtuner.com/features/...val/index.html

 

it worked for a while in the sense that i didnt run with it long term, i fixed it correctly since here in NJ they were still doing emissions testing with the tailpipe sniffer at the time (they dont anymore) so in order to pass inspection it was necessary, however i would have fixed it correctly anyway, im a fan of having things working correctly (the way they were designed to work)

and that article CLAIMS gains, but i want to see dyno sheets as proof, not what some guy i have never heard of wrote about online, dyno sheets (even pictures of them) are solid proof of gains, and btw 5hp (even if it IS true) is nothing that you would notice driving the car/truck around (hell CAIs claim more gains than that and you cant feel a difference driving the trucks after putting them on)

 

No big deal if you don't want to believe anything. However, I've done this to plenty of my older import cars that I used to drag race, and there is power to be had, especially if it is a forced induction car (which is what I used to race), and I also took out my main cat on my '04 Acura TL and was able to tell a slight difference. You might be too young to remember the 80's where government EPA mandates turned true "Muscle Cars" into gutless grocery getters. Now obviously we know the hemi durango is far from gutless, but it's still loaded down with the government nonsense, and anything the government mandates has no positive effect on power.

 

They started in the 1972 with lowering compression ratios, although that was for insurance reasons also. My '69 and '71 are catalytic free and they smell good at red lights with fuel pouring out of the pipes. Liberals make funny faces,
FF

 

The rearward O2 sensors do basically nothing more than report a problem with the cat, so having that sensor bad or removed will not adversely effect performance, just give you the annoying CEL.
A forward O2 would be another matter as it measures and reports to the PCM which in turn will have the PCM changing the A/F ratio in an attempt to reach proper emissions. This will always result in poor performance and really bad gas mileage.

The Hemi engine was designed with a good deal of emphasis on "breathing" and as a result, the stock cats have among the better cfm rates (air flow) in the industry. Many "high-flow" cats do not flow much better. However, at 100k miles, they may be starting to clog a bit.

If you are not in an inspection state, yank them and if the CEL is annoying, do the non-fouler trick to eliminate the CEL. It's also a good idea, because you won't know if you are popping a CEL that might be for a different reason if you don't clear this one or check it with a code reader regularly.

For the "non-fouler trick":

https://dodgeforum.com/forum/3rd-gen...ving-cats.html