nismochasse
NAXJA Forum User
- Location
- US
Hey everyone. I have been having some acceleration issues with my 2000 4.0 XJ. It will stumble, sputter, hesitate, until I get to WOT and then it jumps forward. It is especially bad at highway speeds around 70-80 mph. I have to be at WOT to maintain speed or it will sputter/stumble and lose speed.
I took it to Advance Auto to get the check engine code read and it gave a code for both O2 sensors. I knew the rear O2 sensor would show up as it has had a broken wire for a while, but the Jeep ran fine. I replaced the front and fixed the broken wire on the rear. The issue got worse after this (with the codes still being thrown, the guy at Advance Auto said the computer wont reset them for 500 miles
) and tested the fuel pressure. With the key on and the system primed, it was at 28 PSI. At a warm idle, 32 PSI. After I shut it off, over a few minutes it rose to 42 PSI, then several more minutes it fell to 38 PSI.
Should I go ahead and drop the tank to replace the fuel pump/filter or look more into the O2 sensor codes? Is there anything else I should check before dropping the tank?
Thanks for your time. I hope this all makes sense, I work 3rd shift and just got home.
I took it to Advance Auto to get the check engine code read and it gave a code for both O2 sensors. I knew the rear O2 sensor would show up as it has had a broken wire for a while, but the Jeep ran fine. I replaced the front and fixed the broken wire on the rear. The issue got worse after this (with the codes still being thrown, the guy at Advance Auto said the computer wont reset them for 500 miles

Should I go ahead and drop the tank to replace the fuel pump/filter or look more into the O2 sensor codes? Is there anything else I should check before dropping the tank?
Thanks for your time. I hope this all makes sense, I work 3rd shift and just got home.