Check engine light

[Pointe Watch]

I am new to your board but am a member of an identical board for Alfa Romeo's that has been extremely helpful. It appears this forum has equally talented people and enthusiasts. So, Thanks in advance for any help you may be.
My problem is: Check engine light went on and had a mechanic run the code which came up as - SPARK MISFIRE #2. I had replaced the plugs and thought maybe it was that I had not attached the wires well so I checked all the wires and had the mech reset the computer. It happened again after a couple of days of driving . I don't want to keep paying the mechanic to turn off the code while I find the problem and I don't want to spend the $$$ for the code Reader. Can I shut the code off or read the code in some other way? Without the code reader.
I know some cars you can do that with. Any thoughts what would cause spark misfire? Faulty wires etc.
Thanks for your help.

 

[Blee1099]

Go to Autozone and get the code scanned for free and then post the results of the code scan here and we'll give you some suggestions on how to fix it.

 

[Pointe Watch]

Ben, Thanks but the closest Autozone is in Phil.PA and I only got the code definition from the Mechanic. He said it was plug misfire on # 2 I will try to get the code # if that will help. Couldn't find anything wrong with the wires or connection. I am thinking I may have just gotten a bad plug or it is gapped wrong. Thoughts? I will check the plug again.
thanks for responding.

 

[Positive Vibes]

Call some other auto part stores and see if they can check the codes for free. As said before we need the exact code #.

 

[Pointe Watch]

The code is PO302 FOUND ON THE OBD11 TROUBLE CODE = CYLINDER NO. 2 MISFIRE DETECTED. Hope this helps. Any suggestions on resetting the check engine light.
I have read that disconneting the battery is not good as it takes time for the computer to readjust and the engine will run rough for awhile. Thoughts?

 

[Positive Vibes]

Who told you disconnecting the batter isn't good??? Crock of poo! Yes the computer has to "relearn" but that isn't a big deal. And no the engine shouldn't run rough afterwards.

I would disconnect the battery and see if it clears your codes. It can't hurt anything.

 

[Pointe Watch]

code ?

Who told you disconnecting the batter isn't good??? Crock of poo! Yes the computer has to "relearn" but that isn't a big deal. And no the engine shouldn't run rough afterwards.

I would disconnect the battery and see if it clears your codes. It can't hurt anything.

Thanks for the your help. On the code any suggestions???

 

[98Explorer4x4]

Ever thought of bad sensors?? Might be a stupid and obvious question but ya never know!

 

[Positive Vibes]

Sorry your codes and ECM are different. Mine is a '94.

I did a search and found this thread. Not sure if it will help or not.

http://www.explorerforum.com/forums/showthread.php?t=60916&highlight=PO302

 

[5pointslow]

Who told you disconnecting the batter isn't good??? Crock of poo! Yes the computer has to "relearn" but that isn't a big deal. And no the engine shouldn't run rough afterwards.

ok well im just a 20 year old kid, so take my advice as you wish. disconnecting the battery will work but it is not the most prefered way of doing things. this is because your PCM has to go though a quick-learn process. this may not cause your new car to run rough but an older one with a few miles it may. this is because your pcm stores memory including freeze frames, failure records, statistical filters and i/m readness status. the most important here would be the statistical filtering, this is where your pcm has programmed values for a sensor that may not be working just as new, it's like that old thermometer you have that you know is 5 or 10 degrees off. after all of that, why would you want to clear the codes if you have not fixed the problem yet?? it will just come back! your code is a type 1 dtc. being that it is emmisons related and sets the fail when the enable criteria is met. this also will make it store a freeze frame. what you need to do is find the criteria that it fails under. 2nd is duplicate that criteria. 3 find the most likely cause. i'm guessing that you can't do this because of your lack of tools. but don't just throw parts at it. im now writing this and can't remeber if you had the engine replaced? if so im wondering if the crank sensor has been "learned", should have been done if engine is replaced or sensor has been unbolted, removed or touched in anyway. also things to look for would be vacuum leaks, can be tested easy with a can of brake clean spraying over possible areas for leaks, also an injector problem, switching with another if possible but this wouldn't tell you a wiring problem fords are known for, also as most people know plugs wires, coils, be good to test the resistance both primary and secondary sides of the coil (ground as well) well my head hurts now so this is what i can think of at this moment good luck.
o ya also a good way of testing if you have fixed the problem is remove the spark plug wire of the misfiring cylender and listen for a rpm change if none is there, keep on looking for other problems.
1 more, the code will turn off with the first trip made with no problem found,(shut off the light) 40 trips with no problem will clear the pcm of the code

hope that helps a little
dave

 

[Brain]

Yep, sounds like you need to test the resistance of the wires and coil. You can get a digital multimeter for less than $20 at Radio Shack. Like Dave said, if you fix the problem, the computer will drop the hard code after a while.

 

[Golfmore]

Harbor Freight has a DVM for $3.99. Or it may have gone to $5.99. They work fine.

 

[Pointe Watch]

Thanks

Hey Folks,
Thanks for all your help. Update, I bit the bullet and changed all the plug wires. Seems that the plug shields on the wires grip so tight that when you pull them off many times you damage the ends and start to throw a spark off which the computer picks up. Needless to say - When I changed the plugs the wire ends were sucked on so tight I must have damages a couple wires. All better now. Thanks for your assistance.