The check engine light is on

Asked by Jun 12, 2013 at 12:36 PM about the Ford Ranger

Question type: Maintenance & Repair

Changed plugs and fuel filter, disconnected the battery in the process. check engine has
come after running about an hour around the neighborhood

11 Answers


The Check Engine light is an indicator from the Powertrain Control Module (PCM) that something is out of specs within the computer controlled system. Hook up a scan tool and retrieve the DTCs (Diagnostic Trouble Codes) and go from there. Be aware that a trouble code doesn't necessarily mean that a component is bad except in a few cases. It means that there's a reading or signal that is out of range.

25 of 25 people found this helpful.

Agree with Tracy. Autozone, Advance, and Oreillys (or other chain parts house) all should offer free diagnostic testing, as well as the part(s) and rental (or for purchase, if you choose) tools to fix it, and might even help or change it for you. Might try plain gas and checking gas cap, as well. Friend had the same problem and did 100% plain fuel and tightened the cap, which corrected it for him (won't always work, wouldn't hurt to try though).

10 of 10 people found this helpful.

My 2002 Ranger was doing the same thing. I attached a code reader to the computer under the steering column and it was able to diagnose the problem as well as its general location. Turned out one particular cylinder(#4) was running LEAN which its cause could be anything from a bad spark plug, to a vacuum or air intake leak, to a timing issue. (Lean=too much air not enough fuel...Rich= the opposite). This at least gave me a starting point, i knew to look for an issue on the cylinder#4 side of the engine. Always look at the simple most likely things first. After a basic, yet thorough, visual and audial inspection of the engine compartment (both with and without the engine running), i was able to locate a pinhole leak in a vacuum line. Simple fix, cost about ten dollars for a quality piece of new vacuum hose, took me about ten minutes to replace and has run great since. Here's my advice, 1) Go to any major auto parts store, and have them pull the vehicle's computer codes. This usually takes about five minutes and is typically free of charge. 2) The code reader will give a basic diagnosis and general area of the problem. It will read something like, for example(when I pulled codes on my Ranger): Cylinder #4 running LEAN. or "This Particular" Sensor is not working or Cylinder #X ignition failure etc. 3) After diagnosis is complete, you should have a better idea of where to begin. During this step, it is very important not to over think your evaluation, its always best to begin with the simplest, most likely causes to that particular problem...If you have no spark, start by checking that the battery is charged and properly installed (even a battery connection that feels tight by hand may NOT be tight enough to make contact "personal experience, embarrassing"), then go to the next step; inspect all wiring relative to the battery, ignition coil, starter, and distributor looking for any loose or corroded connection points and checking the overall condition of wires themselves. Any sign of worn insulation on any wiring may point to a potential trouble area and should be replaced. All this should be checked before you can even consider the plugs themselves being the problem. 4) Once the problem is fixed, you will HAVE to hook up a code reader again to reset the codes/computer. Your check engine light will turn off. If it comes back on, usually while driving, after repairs have been made and codes reset, then you have another problem other than whats just been fixed. Pull the codes and start the process again til all issues are fixed. Note: Code reader is required to reset computer in order to turn off check engine light. Also, check engine light will continue to re-appear until ALL problems are fixed. Just check the codes each time for a diagnosis and go from there.

31 of 31 people found this helpful.

VACUUM LEAK TEST SHOWS LEAN DO NOT REPLACE YOUR 02 SENSORS ON THE 4.0 you will find 3 elbos 2 are on the passenger side one on drivers side . Ford sells a kit 2 elbos and the tube but also can go to orieilys auto. first elbo to check runs to you maf air intake if this one is not it under the plastic shield on top of your throttle body 3 bolts holding this on but so much more room when you do . 2nd hose down runs around to drivers valve cover check the hose under plastic cover first . can test with brake cleaner or by looking if you are not to old like me . happy motoring :)

2 of 2 people found this helpful.

Have a ford Ranger showing missing on both one and four cylinder on the exhaust side

6 of 6 people found this helpful.

I had my Mazda B2300 (same as ranger) engine lights on this morning. This afternoon when I came home from work. I decided to poped that hood open pushed all those vacuum hoses to make sure they are tightly connected... Pushed those spark plugs wires to be sure that they are also tight. I cleaned the battery terminals too. After all was said and done. I started the truck and to my surprise... Baboom the engine lights came on...for a second or two then went away. Test drove the truck for about 70 miles so far soooo good no engines be continued...

3 of 3 people found this helpful.

Hey, I have a quick question. I own a 1994 Ford Ranger with a manual 5 speed transmission and a six cylinder engine. My check engine light is on also. Before we started driving the car much, it sat for most of that time (except for an occasional drive). Now, in order to drive it more often, however, we had to change the rubber filler tube because it was worn out and cracked. We just had the filler tube replaced about a week ago, but since we bought the car used a year ago, we haven't changed the oil. My mom was driving the car home tonight and the engine started spuddering and the check engine light came on. Anyhow, we checked the engine oil dipstick tonight, and the engine oil is not full. Could that be the problem or is it something potentially more serious?

3 of 3 people found this helpful.

Get the codes from the computer and go from there. No, the engine oil will not cause a Check Engine light.

1 of 1 people found this helpful.

Thank you very much, Tracy. I hope it's not going to be an expensive fix.


2009 Ford Ranger check engine light came on ticket AutoZone and it will not read what could be wrong with it

7 of 7 people found this helpful.

What does code 4 means

2 of 2 people found this helpful.

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