Check Engine light

[jarheadak]

Hello, to the few who see.
I have a problem, When I go on long trips my check Engine light comes on. It first happened when I went to FL from TN. We got into NC, and had to stop in SC. The dealer told me it was a O scencer. After $400 we headed back out. About, 100 miles later it came on again. Called the dealer, they told me not to worry about it to have it looked at when we got back home. Well, got home dealer here told me it was another O scencer. A year later the same thing happened. Whats up? I have no clue.

 

[MrShorty]

Going to be a little difficult to diagnose from what little the dealer is telling you. We need the actual code numbers and what they've done to diagnose it. On a '95 (most '95's were EEC-IV/OBD-1) you can get codes with nothing more than a jumper wire (I once pulled codes for my dad on his '95 with a piece of bailing wire we found on the side of the road). See tests at www.dalidesign.com/hbook/eectest.html for a good set of instructions. www.fordfuelinjection.com has an easy to read description for the KOEO test using the CEL as the code output device.

As an intro to the problem, O2 sensor codes can be triggered by a lot more than bad O2 sensors. Remember that codes can only alert you to what problems the computer has seen. The computer doesn't know what caused those problems.

 

[JasonF]

Go to autozone get your codes read and replace them yourself... they are $50 each and easy to change with the free loan-a-tool.

Jason

 

[TPLYNCH]

Chances are another issue is causing the O2's to throw a code. Could be a bad Mass Airflow Sensor or faulty Fuel Presssure Regulator. Have you noticed any significant drop in gas mileage since the codes started showing last year?

 

[jarheadak]

Yes, I have, it went from 17-18 to 11-12. Would it be the MAS or FPR or both? I was wanting to replace the MAS in a couple of months, guess it will be soon because of the up and coming trip to FL. Can you or anyone give me idea's how to inprove this?

 

[monkeydude3]

Yeah, my instructor has a 1998 ranger 4.0L OHV and he had a bunch of codes regarding various problems and sensors that ended up being the MAF. He put that in and it ran great, no more codes. Also for the heck of it snug up the intake manifold bolts if you can.

George