My engine light is coming on only in 6th gear, I think its my EGR valve and I am going to check it this weekend. What do you guys think it is?

 

My car does this too. Except it comes and goes quikly (I.e. - will be on for like 30 seconds then just turn off, then maybe 5 mins later come on again.) but only comes on when in 6th at highway speeds. I was lucky enough to get it scanned before it shut off once and was told malfunctioning exhaust o2 sim. Just take it and have it scanned. It doesn't cost anything.

Later