OK, so a month ago about I threw an SES, got it scanned - EGR flow. Redid connection to headers, tighter, used RTV as well - no code for 3 weeks, city driving, 10 hours total above 45mph but below 75mph. So I'm sitting around bored tonight, and I'm like my cars running well...I wonder how cool it stays w/ hwy driving... So After 15 minutes @ 75mph I step it up to 100mph (no fast acceleration/hi reving). I let up, and I'm not going 75-80mph and SES light comes on.

Why? All I can think of is EGR flow again...... But why would it wait till I was on hwy going faster? Does computer need several readings before determining EGR flow malfuntion? I'll get it scanned next time it reads an SES; I pulled fuse for 15 secs to clear code (does that clear from memory or is it stored still?) so it wont come up in a scan... I am curious as to whether or not it will suddenly come on with city driving (then I'll know if the hwy messed something up).

LAST QUESTION: is EGR flow greater in 6th gear, 100mph? Anything extra that would make it more likely to come on? THANKS!

 

I know my light would come on for EGR when I was crusing in the highest gear just after I would let out of it completely.

 

Sounds like what happened to me - what did you end up doing to solve this? Was it EGR flow code or something else?

 

OBD2+EGR+LTs may result in an SES sometimes.

If it keeps giving you problems, I can disable it, but you will still be able to pass emissions.

 

Thanks Ion - I give it another week to calm down before I purchase some blockoffs and have you disable it for me. Thanks again!

 

It's likely the EGR, but I'd go to Autozone and have the code(s) pulled to be sure.