Hi, I've read through most of the forum and have found threads that touch on my problem, but none that address it.

I have a 1998 Mercury Mountaineer AWD 5.0L V8. I've been getting the P0153 code off and on for about 3 months.

I read on another forum that bad gas caps can cause the problem, well, I've replaced the gas cap with a new OEM one and that seemed to help stem the tide a bit.

As it often seems to pop back up when the tank is 1/4 or less, I fill the tank, and that helps some. But it still happens.

This Thursday, 2 days after I changed the spark plug wires, it began misfiring on the #6 cylinder and the P0153 code came back and stayed on.

I swapped the #5 & #6 plugs, cleaned up the area and reinstalled the wires with dielectric grease. No more misfire, but the code did not clear.

So, I also changed the O2 sensor that kept kicking off the code. I used the OEM, Bosch O2 sensor.

I started it and it ran beautifully. Next day, I was driving and that damn code came back. I stopped and had breakfast, it was gone.

Off and on all the rest of the day, disappearing even while I was driving

What gives?????

 

What year is your Explorer and which engine does it have (SOHC V6, OHV V6, or V8)?

-Rod

 

My apologies...I have a 1998 Mercury Mountaineer AWD 5.0L V8.