This is driving me nuts

[mtdees]

Hey have a 96 Grande Cherokee, 6 cly, all stock ....for the last few months it has been cutting out on me when it gets warmed up ....like its running out of fuel, changed the fuel filter, plugs,wires,coil ,same thing
runs like a top when its cool ..but once it heats up ....chug chug chug ....pulled the codes ...said it had a bad O2 sensor ..so tried to get one that would fit ...they make like 9 dif ones ...someone told me to just run it with the sensor unpluged ...so I did ...seemed to fix it for a few days ...then this weekend ..back to the same old thing .....anyone out there have any ideas ........like I said this thing is driving me nuts

[MudderChuck]

Don´t know specifically about the 96, but many computers don´t start reading all of the sensors until the motor gets above 140 F (or so). Next to normal tune up stuff (plugs, distributor cap etc,) the sensors are probably, the major cause of bad running motors. Don´t know, any quick fix or cure, unless you can figure out a way to keep it under 140 F.
Unpluging sensors, other than maybe the 02 sensor, will kill the engine.
Disconnecting the battery and reconnecting after a while (hour or so to give the condesors and such a chance to discharge), can have some short term results (hopefully benefitial).
Be glad, the computer, gave you the answer and change the 02 sensor. Hopefully the computer gave you the right problem, they´ve been known to be wrong.

[XJNick]

Welcome,

Several things to note here:

1) The 02 sensor is a vital part of the computer system. You cannot simply unplug a sensor and expect the car to run properly. All the sensors were put there for a reason, bypassing them is just asking for constant problems.

2) Your Jeep was built after '95 therefore, it has an OBD-II style computer system. These Cannot be reset without an OBD-II compatible scanner. (I believe Autozone can do this for you)

3) Once you've properly fixed the 02 sensor, check the Crankshaft Position Sensor (CPS), Mass Air Temp. Sensor (MAT), and Coolant Temp. Sensor (CTS), as they could be causing problems.

BTW, Mudderchuck, I think you mean Capacitors?

-Nick

	Crank position sensor A crank sensor is a component used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.

[MudderChuck]

Capacitors I was raised in the era, of rectifiers and computers the size of refrigerators.

[sparkyshotrods25]

IT IS THE O2 SENSOR,I HAD THE SAME PROBLEM AND MY CHECK ENGINE LIGHT CAME ON ALL THE TIME.WHEN I REPLACED IT IT WAS FINE.I THINK THE O2 WILL HAVE A FOUR WIRE SQAURE SHAPED CONNECTER ON IT.