So my check engine light comes on for about 10 to 30 secs sometimes longer sometimes less. Then just goes off. It isn't spitting any codes. I've tried several times. The only time the light comes on is goin down the road. What do you guys think?

 

No codes at all? Not even 11 or 111?

 

My old Shortbox reg cab used to do that too. I never figured out what it was

 

Any other issues when the light comes on? Check your fluid levels.

 

Everything is good. No other issues. It just comes on and goes off.

 

Hate to say it but anyone who works on cars knows sometimes you have to wait for the problem to get worse to find out what it is. Meanwhile I would check electrical connections and grounds including the ecu connector. Electrical causes a lot of intermittent problems.

 

I had in the shop today and was doin everything I could to get the light to come on and nothin happened. 2 mins down the road light came on.

 

Don't answer my question. I just won't help.

 

My truck does that after it warms up going down the road I can let it warm up idling no light go down the road light.
I assume its just because I don't have a cat.

 

Mine did that, I brought it to my buddy shop that had a scan tool that could look up previous codes, it ended up being the EGR valve.