sensor of some sort

[jeepmaster]

while removing my cat, i came upon a little sensor screwed into the back of this, my friend and i figured it was an O2 sensor. we couldnt get it unscrewed so we had to cut it, i plan to reaatach it as soon as i can get it unscrewed from the cat. the check engine light came on, and i assume that when i reattach the sensor it will go off. my friend said it was bad for the engine cause it would make it run lean or rich. he said it depends on the car and he knows nothing of jeeps. so im asking you my question should i drill into the test pipe and put the sensor there? what should i do with this sensor? leave it completly off, and if so, how do i get rid of that dang little yellow light. thanks~max[addsig]

[dingus]

that would be the "catalytic converter circuit sensor"... you'll probably be OK driving with it bugging out unless it bogs down the engine... in which case you'll have to trick it somehow into thinking your cat is still installed...[addsig]

[pinaplebob]

I'm pretty sure it senses how much gas isn't getting burnt by the engine and rellays that up to the computer. It's no big deal, not having it there will definalty turn on the check engine light.

pinaplebob[addsig]

[MudderChuck]

Most of the sensors (that fail) will put the computer into and open loop mode. Which will cause the computer to compute some/all functions, by predetermined responses. The end effect, is it will run rich and the timing will be somewhat retarded. And can damage the cat (to rich) but will normally protect the motor from detonation damage. Won´t produce peak horsepower, but will pull pretty good from a stop or up hills.

edited by: MudderChuck, Feb 27, 2003 - 09:07 PM[addsig]

[jeepmaster]

so would re-attaching it turn the light off? and would drilling into the test pipe and mounting the sensor there help anything? or hurt anything? id rather not leave it off because the yellow light is annoying, any ideas?

edited by: jeepmaster, Feb 27, 2003 - 02:27 PM[addsig]

[MudderChuck]

Turning off the yellow light (in my Jeep) is as simple as unhooking the battery letting it sit for awhile (give the condensors a chance to discharge) and reconnecting the battery. Most books recommend, not letting it idle excessively, after re-booting the computer. The computer remembers over a period of the next 20 or so starts, of the motor, to create a profile (at least that´s whats said).
I really can´t tell you if installing the 02 sensor in the sttraight pipe would hurt or help. Sometimes the wrong information, can be as damaging as no information.
You can do like a buddy of mine, I asked him if he ever found the problem that was causing the trouble light to come on, he said yep :-D the bulb.

edited by: MudderChuck, Feb 27, 2003 - 10:14 PM[addsig]

[jeepmaster]

kk ill go try the battery thing now. thanks[addsig]

[seanwheelz]

Question...When I bought my Jeep, as it turns out, didn't have a cat in it, so I didn't have this cat sensor....is it the same as the O2 sensor or is it different? Is it in '87's? If so..could that be why my jeep runs as such a high idle?? I haven't been able to figure this one out yet???
Sean[addsig]

[XJNick]

My '88 cherokee doesn't have a sensor at the cat either . It probably is an O2 sensor and It must only be on later model cherokees :-?.

-Nick[addsig]

[Bounty__Hunter]

It's not a cat sensor, but another o2 sensor same as what's before the cat. They are both needed for the computer (and engine) to function correctly.

Why are you removing the cat? The newer style cats barely restrict exhaust flow, so you gain little or no power by removing it. If it failed, there is an 8yr, 80,000 mile Federal Emissions Warranty and DC will replace it for free. Hi-flow cats can be had for as little as $60.

The pair of o2 sensors is new as of '96 when OBDII was introduced. My '95 YJ only has the one.[addsig]

[jeepmaster]

is anything being ruined by me not having that sensor there?[addsig]

[Bounty__Hunter]

Your gas mileage, not to mention the ruining of the environment by not having a cat :-O And no, I'm not a greeny, just like wheeling in 'Fresh' air

If you pull the check engine bulb, you'll never be able to tell another engine problem has occurred. No way around it.[addsig]

[jeepmaster]

how does cat removal hurt milage? i thought it helped it.[addsig]

[MudderChuck]

If the computer, gets faulty or no 02 sensor readings, it will automatically switch to a safe running profile (hopefully) and prevent destruction of your motor (or serious damage). The safe mode, isn´t the most fuel efficient or cleanest and usually cost overall horsepower.

[addsig]

[jeepmaster]

will having no cat cause serious damage or ruin the engine? i just thought this was a little project, now im kinda wishin i hadnt even started it.[addsig]