I have an 05 Jeep Grand Cherokee bought in 06 with 14k miles now has 202K miles.Oil changed every 4K miles.About a month ago started running rough,stalling,CEL said both banks rich.Turns out the EGR valve was gummed up stuck open.Replaced it & all was good running fine.Then suddenly started doing it again,same thing EGR gummed up stuck open.What could be causing this,runs fine with a new valve in it.Just before it started running rough the 2nd time the service electric brake system light came on.but then went off at the next startup.
Thanks
Sal