That stupid CEL

[mvp]

I was wondering if someone could help me, I have a 97 XL and for about the last 4 months the CEL has been on. It idles perfectly but misfires under load. This misfiring seems to get a lot worse on a long trip, sometimes to the point where it won't go up a hill. I also notice that it has been using a lot of petrol. (probably due to the misfiring) I live in Australia and the Explorer is not a well known vehicle over here. When I take it to a mechanic they all tell me to "Buy a Toyota". I have changed the leads,plugs, Oils, Filters. My last piece of advice was that the CEL didn't do anything, I have read the other threads about the oxygen sensor. Are my symptoms consistent with this sensor breaking down.? I have been previouslt told that it is probably something wrong with the pollution gear. I would appreciate any help.? Thanks

 

[aldive]

I think I would run a diagnostic check of the main computer and determine of it is giving you any trouble codes.

Good luck.....

 

[mrboyle]

aldive, that would be my advice also, but being in Australia he may have a hard time finding anyone with the proper equiptment to scan it.

As for the problem there could be several causes. First and foremost the "CEL" does do something and it is there for a reason, don't ignore it. The missfire is what is setting the CEL. First, you said you changed plugs, wires, oil and filters, does that include the fuel (petrol) filter? If not change it, if so lets go further. What needs to be done is to next determine which cylinder/s are miss fireing. Once that has been determined you can focus on fixing the problem. Test the fuel injector, wire (I know its new, but do it), plug and coil pack for proper opperation. If everything checks out try a compression test as well as a fuel pressure test. The list of things to try goes on and on, but it is necessary to start with the basics and work your way to the harder stuff untill the problem is cured.

 

[aldive]

Those darn O2 sensors can cause a world of problems. Take a look at the thread called "Alarm System Woos"; it details a problem I had with the O2 sensors.

Good luck...

 

[Ray Lobato]

The chances that your O2 sensors are bad is very good, however you might have other problems too. If they are not fixed, then if you put in new O2 sensors, they will go bad also. Change the O2 sensors, and make sure that your fuel regulator is good. Get the injectors cleaned, then see how it is running. If the above doesn't fix your problem, don't run it for any length of time as it will ruin the O2 sensors that you just put in.
good luck, and please keep us updated.

 

[Robert]

Even in Australia, it shouldn't be too hard to find a shop that has an OBD-II scanner. There should be several different US brands sold down there and they all use OBD-II diagnostics. What about the Ford dealer that sells them? If anyone has one, they should. Worst case would be if you have to buy a scanner yourself. One that will just read the codes for you runs less than $140 US at Summit Racing. I don't know if they export though.

 

[mvp]

O2 Sensor

Thanks for everyones help. I finally found a Ford dealer that had the ability to read the computer. He initiallt told me that it was probably the inlet manifold. I told him that everyone on the internet told me to check the 02 sensor. He checked it and it was stuffed. I am now waiting the 2 weeks for you guys to send one over.
Thanks very much for your help