hello all i own a 1991 740 and i keep getting a check engien light is there a easy why to find out what is wrong with it ... it is on for 3 drives then off for 3 drives please help need to get it to pass inspection

 

there is a little black box on the drive side strut tower:


Pull the codes, if any, and report back. here is how to check for codes: http://www.troublecodes.net/Volvo/

 

thanks i will try that where is the selector cable ??

 

The cable should be attached by a cable to the inside of the little box.

If your check engine light keeps coming on then it is telling something.

Depends on what your doing prior to the light coming on.
For example: I went to get gas the other day...and I filled her up with 91 and I drive out of the lot and BAM! check engine light. I pul the code 1-4-3, which is the knock sensor, but it was just some bad mixture of gas which set it off. A couple weeks and still no light.

 

i checked my codes and it has 2 .... 2-2-1 and 2-3-3

i read the page you sent me what you think i need to do ???