Check engine light came on today
that explains it. If it is gutted then your rear O2 sensor should read LOWER readings. Since they are roughly the same as the precat sensor...it tells the computer that your cat is not working.
Get an O2 simulator: Only for post cat O2 sensor(s)
http://www.thefastman.com/o2simm.php
ran one with my 1996 with a gutted cat. Weirdly, I got a bump in MPG and better driveability. Same as Drew was talking about after changing his post cat 02 sensors (Us Cali trucks have 2 precat and 2 post cat).
Get an O2 simulator: Only for post cat O2 sensor(s)
http://www.thefastman.com/o2simm.php
ran one with my 1996 with a gutted cat. Weirdly, I got a bump in MPG and better driveability. Same as Drew was talking about after changing his post cat 02 sensors (Us Cali trucks have 2 precat and 2 post cat).
Over all for $75 that might be a good and simple fix.
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Joined: Apr 2010
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From: Clayton MI
That is tempting. I could replace the cat with a pipe. The only thing I would be worried about is actual unit. Where does the unit sit? If it's replacing the O2 sensor wouldn't it be pretty low? It says moisture resistant. What happens if you drive through water?
Over all for $75 that might be a good and simple fix.
Over all for $75 that might be a good and simple fix.
) Basically, you could put it wherever you wanted to. Even in a sealed box.
The O2 sim is just that. a simulator. Doesn't need to be near the exhaust at all. You could run the harness for it into the cab, and have the sim in the passenger compartment with you.... (I would hope you don't get water in the cab very often....... ) Basically, you could put it wherever you wanted to. Even in a sealed box.
) Basically, you could put it wherever you wanted to. Even in a sealed box.
. Are the wires long enough or do you have to add to it? I may have to do this. I'm going to ask my brother if he'll cut my cat out and weld a new pipe in. The check engine light could be gone fairly quickly with this.Should I add the sim and see if the code comes back before I mess with the cat?
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Joined: Apr 2010
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From: Clayton MI
You could conceivably just pull the harness out of it's clips on top of the trans, and put the sim up by the brake booster. Depends on how much of the harness you can free up, and how long the pigtail on the sim is. If nothing else, extending the wires shouldn't be too much of an exercise.
You could conceivably just pull the harness out of it's clips on top of the trans, and put the sim up by the brake booster. Depends on how much of the harness you can free up, and how long the pigtail on the sim is. If nothing else, extending the wires shouldn't be too much of an exercise.
Registered User
Joined: Feb 2012
Posts: 15
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From: southern KY
I've currently got the fouler trick installed on my 97 Ram, I've got a true dual exhaust with no cat at all. My check engine light went away when I did the fouler trick, however I had been wondering the same point that was brought up in an earlier post here -- wouldn't I get a little better mpg and better driveability with the simulator installed instead, since it would be giving the motor the exact readings it was looking for? or not?
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Joined: Apr 2010
Posts: 87,400
Likes: 4,214
From: Clayton MI
I've currently got the fouler trick installed on my 97 Ram, I've got a true dual exhaust with no cat at all. My check engine light went away when I did the fouler trick, however I had been wondering the same point that was brought up in an earlier post here -- wouldn't I get a little better mpg and better driveability with the simulator installed instead, since it would be giving the motor the exact readings it was looking for? or not?
Legend
Joined: Jul 2011
Posts: 8,259
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From: Austin, TX
jmpar20, you could test this and let us know ! ! ? ? !
Registered User
Joined: Feb 2012
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From: southern KY
well, i could. i just wondered if anyone else had, thought it might save me about 75 bucks plus shipping. lol. but if i dont get an answer soon i may do it anyway, i thought i'd see an improvement in mpg when i did the tb mod, installed a cold air intake, and had a true dual exhaust installed, but it's honestly about the same as it was before