Oxygen Sensor

[3312DC]

Hello... first post so please be nice.
Have a little problem with my buddies 93 Jeep Wrangler (4.0 5speed). The engine was not running at max power, and making a strange whistling noise. The power loss was so bad the jeep was having trouble making it up steep roads. Thought it might be the oxygen sensor, so I disconnected it and the jeep ran the same. So I figured the oxygen sensor was bad. THEN (this is the real problem) the owner of the jeep decided it would be a good idea to jump the oxygen sensor. So he took power off the car battery and "jumped" the plug were the oxygen sensor usually plugs into. Now the car wont start. We dont have any ignition. Did we fry the computer? or something simpler.... please help.

Cale
2000 XJ, 90 DSM, 86 CJ7, 93 Wrangler

 

[GreenReaper93]

So he took power off the car battery and "jumped" the plug were the oxygen sensor usually plugs into. Now the car wont start. We dont have any ignition. Did we fry the computer? or something simpler....

Yeah, that's not good..... Um, when you say you "jumped" the plug what exactly do you mean? Did you touch the sensor itself?

P.S. - WELCOME TO THE BOARD! You'll meet a lot of friends on here... that's no lie. Glad to have ya, and don't be scared :lol:

 

[BostonJeep]

Hehe ALL jeeps have trouble making it up steep roads! but , if its a serious loss, sounds like a fuel pump problem to me... if the o2 sensor was bad it would just make your gas run rich, with bad mpg.

i had a similar problem with my jeep losing ALOT of power too, and it was the fuel pump. Sorry cant help ya with the computer stuff , but just trying to give ya another idea on what could be wrong.

ps welcome to the board!

 

[Bounty__Hunter]

Probably a plugged catalytic converter. Run with the o2 sensor out of the pipe and see if it has more power. You can get a hi-flow replacement cat for $60.

 

[jeepin916]

well if you jumped the harness of the oxygen sensor then you fried the oxygen sensor but if you jumped the other harness comming off the main engine computer harness with 12v battery you fried the computer the car would still run even if you had a bad oxygen sensor mines bad right now it just runs rich....
that wasnt really a good idea to jump the harness with 12v hehe and :wink:
welcome to the board

 

[XJNick]

My new ride

Welcome,

If you applied battery voltage, that is 12 volts, to the computer end of the wiring harness, that's bad. Usually, the O2 sensor outputs about 1 volt max. That means there is a good possibility you've fried that computer.

Good luck
-Nick :!:

 

[Snitty]

i was just thinking, was there any reasoning behind "jumping" the O2 sensor? i agree with the previous statement about the fuel pump... i am having similar problems, and i think it is my fuel pump... injectors are opening right, air is getting in, timing is perfect, all sensors good... just can't get the power i need... fuel pump is my next dark shot

 

[Bounty__Hunter]

If your power loss becomes gradually worse from when you start the cold engine to when you've been driving a while, probably the catalytic converter.

 

[Snitty]

my power is great when i first start the jeep... then when it warms up, it poops out on me... BIG flat spot at about 2200 rpms... i have no cat

 

[3312DC]

1994 Mariah 18' boat

Actually... I was wrong... my buddy jumped the oxygen sensor with itself. he used a cotter pin and connected two leads together.... Do you all know where I can get a new computer? am I going to have to go through the dealer? And I belive you might be right about the catalytic converter... I found out the car has been run on AvGas... which contains lead.