Any ideas? My 2000 ford taurus check engine light is on and off. Already replaced EGR valve & gas cap.?

You can sure spend a lot of money without getting the codes first. My guess would be DPFE sensor for a EGR code, or bad intake o-rings and seals for lean codes.

I agree with Dave. You can show anybody how to pull a code, but that only gets you going in the right direction. They will sell you a bag full of parts and you will still have a SES light.

The "Check Engine" light or "Malfunction Indicator Light" (MIL) is triggered by the PCM when the PCM identifies a circuit or system that it monitors as being out of range.

It is NOT indicating a failed component, but a whole system or circuit.

If for instance you get a code for an Oxygen Sensor circuit (P0171), the indication COULD be a failing sensor, but most likely a fuel control issue.

If the fuel filter is slightly restricted, the computer gets to a place where it can no longer add enough fuel to compensate, then it sets a code that the system is too lean (P0171).

If there is a vacuum leak, same code. If the MAF gets splattered with bug guts (a common occurrence), again a lean condition.

It is for this reason that merely throwing parts at the problem is profoundly wasteful and ineffective.

It is best, if you have the ability to perform your own repairs, to ask the nice fellows at the discount parts store to retrieve the DTCs for you.

Write down the CODE, and the description, and while you are at the store purchase a repair manual for the little car. If they don't have one, get one at the book store. If that fails, go on-line (BN.com, Amazon, etc.) or go the library and use what they have.

Another option is to go here------>

http://www.eautorepair.net/

...and for a modest annual subscription fee, you have access to ALL of the repair data published for your car. This includes repair information, assembly and dis-assembly, diagrams, illustrations, DIAGNOSTICS, recall and TSB information.

Do the diagnostics, follow the trouble tree and repair the problem and not the symptom.

Your repair will be more correct and will solve the problem. You will save time, money, effort and frustration.

If all of this is unfamiliar to you, or you just don't have the time, then bite the bullet, pony up and take the car to a REPUTABLE repair facility or the dealer for diagnostics and repair.

Good Luck and Merry Christmas

I had this problem with my 2000 Ford Taurus. I had the car calibrated and the fuel pump replaced. I would have never have guessed that to be the problem. Supposedly there is a part that mixes the amount of air and gas going to the engine which made the check engine light go on and off. This also made the car run a little ruff. The light would go off and actually run better when I would put higher octane gas in the car which the dealership does recommend doing. These engines are made to run on 87 octane gas. Since I had this done the light has not come on again. The total repair cost about $250.00. This repair is not covered under warranties that I am aware of. Hope this helps.

You need to have a computer diagnostic scan done on your vehicle. Do not let a parts store like auto zone etc. touch your vehicle. Any body that thinks a parts sales person with a cheap code reader can diagnose your vehicle is nuts. The code they give you is usually not the problem. If somebody tells you oxygen sensor ask them which one they are guessing at. Up stream, down stream, bank-1, or bank-2. At $ 100.00 each. Instead of asking people to guess what is wrong with your vehicle It will be cheaper to have it properly diagnosed by a professional.

find a mechanic with a computer for your car, have him hook it up, reset the ECM and see if the code pops up again. If it does have him check the code and figure out what needs to be fixed, check engine lights are not just for gas caps and EGR valves.

It should ahve stored a code, go to an auto parts store and see if they will loan you a code reader, Most do.

You might change the air filter. Look for a code first. It may be a short in a sensor.

Go to Advance Auto, or Autozone and get a diagnostic done on your car. It's probably an O2 sensor.

I like the O2 sensor as well, but you need to get the code diagnosed. Advance Auto Parts will hook up their code checker to the diagnostic port on your car and that will tell them what your car thinks is wrong with it. They can reset the codes as well.

Best of all, it's free.

Oxygen sensor.

Edit: The questioner asked for ideas, not a diagnosis. It would appear that O2 sensor was the common answer. It goes without saying, that a professional diagnosis would be required.