Service engine soon light?

Question

Why is it that this darn light comes on and off intermittently? Like it'll last a day then turn off then come back on.... I've had it checked out and they say that there is nothing wrong with it.... the code it was pulling originally was for an oxygen sensor, then they said that it needed a fuel injector service cleaning and I did that so what's up? Is the light just acting up or is there and underlying problem that they can't figure out or detect?

Thanks!

Answer 1

If there is nothing wrong, then I suspect the light is faulty, you should take it to your dealer.

Answer 2

the check engine light will come on when the computer receive a signal that a sensor value is out of range. the light  will stay on until a predetermined number of  cycles is done without an value out of range. a cycle is normally started when you turn on the ignition and done when you turn off the ignition

Answer 3

First read your guide for your automobile and check out what it says for the "check engine' light. All vehicles are different.

It may be your oxygen sensor itself, causing the light to come on intermittently.

If you really want it checked and don't mind paying the charge, I would take it to the dealership for your make of car.

Answer 4

It comes on for maintenance.  Like an oil change or a major service like 30000 miles.

If the check engine light stays on, then something could be wrong.

Answer 5

This might sound dumb but check to make sure your gas cap is tight. This does cause the light to come it happens all the time.

Details: I have worked at a GM dealership for over 15 years and this is the most common thing.

Answer 6

Mine comes on everyday. By now my engine should have blown up. Every little thing makes mine come on. I have my engine serviced regularly. It comes on when the oil needs changed and stays on even after it's changed.

Answer 7

You need to get someone with a clue about cars.  Sometimes an oxygen sensor goes off for just a clogged air-filter, and sometimes for a serious problem; preferably ASE-certified.

Answer 8

Was your Car connected to a Diagnostic Analyzer, like a Snap-On Scan Tool ? Also, it could be something as simple as a faulty Gas Cap.This can cause the Evaporative Emission Sensor to go off intermittently.Stranger things have happened.

Answer 9

Almost every car I have ever owned with a check engine light randomly has it turn on. It used to be frustrating but after a while, every time the diagnosis was that the O2 sensor was malfunctioning. So I just don't worry about it anymore. I get regular tune-ups and oil changes, and listen for weird noises and such, and just ignore that light!

Answer 10

in order for a CEL (check engine lih) to come on, the sensors need to send the same error  X amount of times in  single cycle.  means that there cold be a faulty sensor.  go to autozoe as they can scan your car for  free and tell you what the problem is.  they cant fix it but you can at least know what the problem is.

Answer 11

U can disconnect the negative battery cable for a min or so and it will reset your pooter.  If it comes back take it to autozone and have them read the code, its free.  I to had this prob and it was my o-2 sensor, doesn't hurt vehicle but bad for environment.  I finally changed it and no more light.

Answer 12

Get it checked out, and have them look at your control panel computer in your car, seem the sensor is fryed or something

Answer 13

well no car listed so, hard to pinpoint,but, an intermittant check engine lt and an 02s code most times means one of the o2s heaters is not working. Which o2s I can't tell you, most late model cars have 3-4 of them. sounds like a o2s heaters not working to me. One of the 02s is not responding within the time limit with the others. this could mean a vacume leak, fuel fouled oil, in need of a tune up, axhaust leak, poorly maitained car ect. But, sounds like a bad heater in one of the o2s's.

Answer 14

find another garage. i dont think these guys are on your side.

Answer 15

the shop needs to be able to understand what their scanner is saying.if all they have is a code reader then all they are doing is guessing.a doctor can't tell you that you broke your wrist without an X-Ray and the ability to read it correctly.try a place that specializes in diagnostics. my guess is that the 02 sensor is failing by reacting too slowly (lazy) which will cause an intermittent "service engine soon "light to come on and go off by its self.