Service Engine Light

I own a 1999 Tahoe. When I pull my 14' trailer or drive in excess of 80 mph for 100 miles or more the light comes on and stays on for a couple of days then go off. Does anybody have any suggestions on what could be causing this ?? It has happened about three or four times.  

                                                                        Thanks,

                                                          Dondobe

 

 

    The problem that was causing my Service engine light to come on under these conditions was my cap & rotor. There was a lot of build up on the terminals, making it misfire under a load and higher speeds.                                            

                                                            Dondobe 

I have had the same problem with my 99 Tahoe when I tow my 5x10 trailer loaded down. The light usually comes on when I am going up a hill and the truck shifts out of overdrive to take the hill. I had it scanned and the only thing that it showed was a misfire code. I was told to drive in 3rd instead of OD when towing. Wish I could be more help.