MY CHECK ENGINE LIGHT CAME ON THE OTHER DAY AND I PRESSED THE BUTTON BY THE LITTLE LED UNDER THE HOOD AND THE LED BLINKED 5 TIMES WHICH IM TOLD IS EGR.. OK .. WHEN I PRESSED IT AGAIN THE LIGHT BLINKED FOUR TIMES..(AIR INJECTION??)).. THE NEXT TIME IT BLINKED 5, THEN 4 AGAIN.. IS THIS THE NORMAL WAY FOR THE SYSTEM TO DISPLAY MULTIPLE CODES OR DO I HAVE A PROBLEM?? ALSO,, IF THE CODE 4 IM SEEING IS REAL.. WHAT MIGHT NEED TO BE DONE TO FIX IT?? ANY HELP WOULD BE GREATLY APRECIATED/// THANKS