I've always had the ses light turn on after running a few minutes on the highway in 6th at about 50-55. I'm going to get it checked soon, I don't know much about the codes but i'm guessing its going to tell me that its running excessivly rich. I was curious how long the code will stay in the computer though?

 

Till you kill power to the computer or unhook the battery.

 

I thought also by the time you shut the car off and on 50 times to code gets deleted.

 

yeah the PCM will automaticly shut if off after 40 warmup cycles AS LONG as the problem has been corrected

 

I have the exact same problem. It doesnt do it any other gears only 6th and sometimes will shut off after some city driving. It never has come on 1st-4th and only once in 5th. Is it serious, any ideas? Most shops close after I get off work so kinda hard to find time.

 

Most likely EGR related.

Some codes disappear from stored memory after a certain amount of drive cycles. The number of cycles is dependent on the code.