Running Like Garbage

[nickcatt]

I got it figured out. On the rear of the upper intake manifold facing away from when I was looking at it was what looked liek the worlds largest vacuum leak. I was going to take the upper intake manifold off to see if the o rings were bad (more of a double check because I replaced them when I bough it) and i realized there was another line on the back of the manifold that I was stuck on. So I went to take it off and discovered a huge gash in the line. There was my problem!

 

[RandomNerd2000]

I know that the SOHCs are a PITA with leaks, I had a leak on my 2001 I hunted six months, fuel pump was bad too, but even afterwards it'd run lean, well turns out my upper intake was WARPED, no idea how that happened but a trip to the junkyard, $10 later, and no more leak.

 

[swshawaii]

I got it figured out. On the rear of the upper intake manifold facing away from when I was looking at it was what looked like the worlds largest vacuum leak. I was going to take the upper intake manifold off to see if the o rings were bad (more of a double check because I replaced them when I bough it) and i realized there was another line on the back of the manifold that I was stuck on. So I went to take it off and discovered a huge gash in the line. There was my problem!

Nice, easy solution for a 4.0L SOHC thread that often ends with a scrapped Explorer. Congrats, and keep the oil clean. LOL

 

[fast_dave]

I did get a code for a toasted one and I replaced it. It made it run like it should for a day or two then it was back to the same old

FWIW: Any time you replace an Oxygen Sensor (or plugs & wires) you should re-set the computer, as the computer has a built in algorithm to adjust the engine operating parameters for the O2 sensor age & degradation.

Also - O2 sensors are reasonable enough from Rock Auto (w/ the Serious Explorations 5% Discount) that after what your EX just experienced, you really ought to replace all of them. What you spend in $$$ you'd save in fuel as well as an increase in performance.

 

[J_C]

^ That could be why it ran better for a day, till the computer relearned and leaned the fuel mix. Some people automatically disconnect the battery any time they work on a vehicle. I don't, well I do it more often on vehicles with electric fans.