1999 Ford Expedition Odd acceleration problem.

KYTRUCK

MEMBER
1999 FORD EXPEDITION
V8
4WD
AUTOMATIC
65,000 MILES

I have a 1999 expedition the motor went out on us, so we had it replaced with one from a 2003 expedition with 65k miles. Since then, when I give it gas it seems to accelerate very choppy and slowly, unless I get the rpm's really high, and then it run just fine. The check engine light is on and indicates a Oxygen sensor is faulty. But I didn't think that an oxygen sensor would cause that much trouble as I have had numerous vehicles with o2 sensors out and ran them with no problem. I did so far replace the fuel filter to no avail. And the fuel pump is also only around 4 months old. One thing I did notice is that towards the rear of the vehicle you can sometimes smell gasoline.

Wednesday, August 4th, 2010 AT 1:22 PM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

First, we always recommend staying with direct fit parts because things change from year to year. As a result, problems like this happen.

Regardless, I have a couple questions, since you smell gas at the rear of the vehicle, I have to question a leak. Have you checked fuel pump pressure? If not and need directions, let me know. Also, have you checked for vacuum leaks? And yes, a bad O2 sensor can cause many different problems. It tells the computer what the emissions from the engine are and the the computer responds with more or less fuel. Have you checked the catalytic converter to make sure it isn't plugged?

Let me know.

Joe

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Wednesday, August 4th, 2010 AT 5:41 PM