i have this 09 vision with code 2961 egr temp hi it has 1191 counts and code 1966 has 2 counts both are inactive the bus runs great drive called in complaining the stop engine light was on so i went out there to exchange buses when i got there i started up had no lights it ran great but had these codes itran great all the way back to shop with no problems would a stickin egr valve cause this i dont think a clogged tube or cooler would do it or it wound happen all the time any ideas?