QuestionI recently got this truck 92 F 150 4.9 liter, it has been sitting for two years. the guy I got it from said it had a blown engine. After repairing the oil leaks and tune up it runs great,my question is that the check engine light comes on and off but not in any specific order. Now and again the engine sputters and then stops. Do I have to change the o2 sensor or any other sensor?
Also the rear ABS light comes on and off what do I look for there?
Thank you.
AnswerHi Chuck,
Sounds like you got a good deal.
There are a lot of things that can make the light come on, and many of them are not too serious at all.
What you will need to do is read the stored fault codes.
That won't necessarily tell you what to replace, but it will set you in the right direction.
Just keep in mind that a code for a rich O2 sensor, for example, does not mean the sensor is bad.
If there is a dirty injector, or something causing a rich mixture in the exhaust, such as a bad plug wire, etc, the exhaust will be rich, and a properly working oxygen sensor will detect that.
It will send a signal to the computer, which may try to correct the rich mix, but may not be able to do it. Therefore...a rich o2 sensor signal.
Vacuum leaks will set a code. There are dozens of little things that will set a code.
The ABS is the same way. A little air in the system....a wheel speed sensor dirty...need to read the codes, and then look in a service manual troubleshooting section to see where it says to check.
Many of the sensors can be checked with a ohm meter, and loose wire connections can allow moisture in, or intermittent connections, and set a code.
Codes are what make the lights come on.
A light that just comes on now and then, and then goes off, is usually an intermittent problem, and if the light doesn't stay on, and actually blink, then it isn't considered serious.
A loose gas cap, or leaking vent in the gas tank will even turn the light on in many Fords.
Van
