99 running bad after start

[mlv1234]

so i have a 99xj and it cranks right up but then when i get driving or let it sit it starts to idle rough and when im driving it will start sputtering but if i floor it it will clear right out. but when i shut it off for like 5min then restart it does the same thing. the codes its trowing is both O2 sensors are bad but i replaced them and same thing. fuel system cleaned, plugs, wires, cap, rotor not sure what to do next need help

 

[joe_peters]

Only when hot?

Search "heat soak".

 

[mlv1234]

hot or cold it does not matter

 

[joe_peters]

Could be a number of things, bad injector, too high fuel pressure, bad wiring to o2 sensor.

I guess I would test the fuel pressure first.

 

[mlv1234]

i took a pressure on the rail and it was fine. the funny thing is that the check engine light is not alway on some day it will be and some it wont im lost

 

[joe_peters]

Did you try taping the gauge to the windshield and driving it to see if you can verify fuel pressure under different loads?

Duct tape--man's second best friend!

 

[mlv1234]

no i did not thats a good idea ill do that. i think i read somewhere that there was a recall and the computer needed to be reflashed has anyone heard of that

 

[joe_peters]

I remember some posts about that, can't remember year/reason for it.