Once again the check engine light has come on. This time it has been unknown to me. First it was flashing for about 20 seconds, then stayed on for the rest of the trip home. I did stop at the local bank to check it out. Turn Truck on/off light stayed on. I have no clue what it was. This just happened not less that 10 minutes ago. So in the morning I'll give you a run down of what happend through out the day. I've been having problems with the alternator, but that's been fixed. So currently I'm clueless.

4.6L 2wd XL. Stock.

 

blinking ck. eng lamp

a blinking ck eng lamp indicates a misfire, one that can cause catalyst damaged if not corrected soon due to excess fuel (unburned fuel) being dumped into you cat causing it to melt together.

 

This same thing just happened to me last weekend, check engine light flashed about 20 times and then stayed on. I reset the computer and had it happen again, so I started looking under the hood and found the problem to be a plug wire that was either improperly installed when I changed the plugs or it backed itself off the plug and was making the number 3 cylinder misfire.
MY .02! Check all your plug wires and make sure they are seated properly, then reset your computer by disconecting your battery four about 10 seconds, then reconnect it, start truck and test drive.