How do I know if the 02 censer in my 96 Cherokee is bad?

Question

It starts hard after it warms up and floods itself so that I have to step on the gas peddle to make it idle.

Answer 1

that dont sound like a 02 sensor, sounds more like the idle control sensor. check to see if you are having any codes coming up.

Answer 2

it sounds more like your fuel press regulator is leaking  it can be tested by pulling off the vacuum line  starting the car   does it leek fuel  replace it

Answer 3

take it to a dealer. these cars stink

Answer 4

Sounds more like an idle air control valve to me... Since it is a 96', your vehicle is equipped with an OBD II port... If your check engine light is on you can have it checked through this port at Auto Zone for free. Try cleaning the IAC (Idle Air Control Valve) before you spend a bunch of money.  

Answer 5

.........an o2 sensor CAN cause the problem you have............HOWEVER it would be a good policy to replace the plugs ...(probably gas fouled.....also check the spark intensity at the wire ends.....)   may need a plain jane tune up depending on how long the system has been neglected and running bad.  vacuum leaks at the intake manifold vacuum ports can cause the same problem also, by causing the system to run lean and the puter to try to compensate for the lean problem by ENRICHENING THE AIR FUEL MIX.    (thus fouling the plugs)

................would be a good policy to replace the o2 also at this time ....if it IS deffective it will cause a reoccuring problem.  a scan tool is needed to check the sensor and the codes and to clear everything after repairs are made.