My check engine light came on today out the blue. my truck runs fine so i have no clue what it could be. anyone got a clue?

 

You'd be best to go to autozone and get the code read. They'll do it for free. A lot of times the light will come on, but you will notice no difference in how the vehicle is running or performance.

 

no way for us to geuss what it is untill you get the codes read. like stated above, autozone will do it for free. get the codes and post them here.

 

thinking of just taking it to my mechanic on tuesday and let him do a once over. need this truck for a long trip coming up.

 

did u fill up your gas tank before it came on? it could be something as simple as your gas cap leaking or not being on all the way.

 

put a piece of black electrical take over the light, my dads old 96 3.0 had the same issue, and he was driving up to the top of mountains everyday with that thing

 

i know this isnt the right engine forum for me, but thats usually what causes my CEL lol

 

PDFE sensor is my guess

 

Could be O2 sensors thats why mine came on got them replaced and haven't seen that light since.

 

There are million different conditions that can cause the light to come on. The only way to find out is to have the code read and go from there. Guessing is useless and so is ignoring it. Find out what it is, then decided if you should ignore it.