Just the O2 Sensor?

[kubben]

I searched and didn't find the answer and wasen't sure what thread to add it to so I'm making a new one.

I have 68k on my 1996 XLT. Gas mileage has gone way down then bam Check Engine. I took it to the dealer for code reading and they said it was the O2 sensors.

I read on this site you are to change your O2 sensors about 100k well I only have 68k and my sensor's are already out. Could this be normal?

 

[BExplorer]

Sensor...

Watch for the FPR(fuel pressure regulator) it cant make your O2 go bad before there time, in fact I have to change mine because of this. You can change your O2 and for a time it will work good and then give you the same code again. Do a search on the FPR it will answer most of the diagnos question.

 

[JT]

I ran into the same issues just recently, my truck is around 63,000 miles. Right around 60K my EGR went bad, and at 61,000 one of the o2 sensors went bad. I was getting like at my worst 10 miles to the gallon, and i do alot of highway driving (about 170 miles a week) Now i am getting 16-18 miles a gallon, and truck is running alot better. You'd be surprised how much of a difference it makes. I wouldnt hesitate to get the o2 sensors replaced. Have them check your Fuel Pressure Regulator also.

 

[kubben]

So you had to replace your EGR and your O2 sensors?
Isn't EGR some pollution regulater or something down those lines, probably wrong on that.

Anyway to check your FPR at home or do they have to hook it up to a machine?

 

[JT]

EGR is the Exhaust Gas Recycler, some people call it a Pollution pump. It keeps the engine running efficiently.

 

[Rhett]

I am assuming you have the 4.0 OHV motor, I didn't look at your sig.

One way to check your FPR is to check to see if you have any fuel in the vacuum lines. Look on the back of the driver's side valve cover, toward the back of the engine. There should be an "octopus" fitting which has varous vac lines going out of it. Pull the one that leads to your FPR...it's tough to figure out which one that is, but it can be done...and if fuel spills out then your FPR is bad.

Of course, this test is not foolproof, it's just an old garage trick. There is probably a better method in a Haynes or Chiltons manual but I don't know.

The FPR is located towards the front, roughly on top of the engine, by the fuel rail. It's sort of "down in there" with some hoses above it. It will have a fuel line fitting and a vac line fitting among other things.