For some reason I only get a check engine light when I drive my 1994 v6 manual at high speeds for an extended period of time.

I can drive around town and no light.

Having trouble reading a flash code as well. The light resets itself after truck is shut off.
:i con_attention:

 

You will need to get the code to find out what it is.

 

You've done the key dance and you get no codes at all?

 

Hmmm...took a 175 mile trip the other day, no light at all. Wonder if hot weather is to blame?

 

Until you get the code read you will never know.