1999 xj surging and stalls out, need help!

I have a 99 xj 4.0 auto that runs great but the engine surges sometimes when I hold the throttle between 1500 and 2000 rpms when in 3rd gear or overdrive. It also sometimes misfires and sometimes stalls out when idling or going slow. It misfires the most when going in reverse or making slow turns.

The check engine light comes off and on throwing codes, P0107 Map sensor and P0112 Intake air temp circuit.

Im trying not to just throw parts at it, anyone know what this might be. I also just changed spark plugs, distributor cap and plug wires.

i have a 99 xj sport and had the same prob than i changed the o2 senser that on the header and it fixed it had the same codes and everything

Ok thanks I may try that, I also have the famous exhaust manifold crack, I wonder it that could be throwing off the o2 sensor?

i dont know im not that smart with all that stuff i just hade the same issue with my 99 you can cut a pop can and rap it round your crack with some clamp might help you can get both u can get both o2 sensors for under 100 i would do that i will bet money it will fix it but fix that crack first i

dustin88 said:

.........The check engine light comes off and on throwing codes, P0107 Map sensor and P0112 Intake air temp circuit.

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Have you tested the MAP sensor and the IAT sensor for proper function and tested their wires for short or open circuits ?


A cracked manifold can most definitely cause strange readings at the O2 sensors. It lets fresh air into the exhaust stream.