Originally Posted by Pegleg302

O.k. Since I Said I Am Going Through This Also, But With State Emissions Test On Top Of It (failing For Nox) I Have Been Testing Everything I Can Test With A Vacuum Pump And Digital Vom. TODAY I PUT ON A VACUUM GUAGE TEED INTO THE EGR SO I CAN MONITOR IT WHEN DRIVING. EGR FUNCTION IS DIRECTLY RELATED TO NOX CONTENT IN EMISSIONS TEST. IF THE EGR OPENS AT IDLE YOU WILL HAVE STALLING, ROUGHNESS, HESITATION. IS YOUR EGR CLEAN? IS THE PISTON ON THE VALVE SEATING? YOU CAN TAKE OFF THE EGR, POUR SOME ISOPROPL ALCOHOL OR OTHER THIN SOLVENT ONTO THE PISTON TO MAKE SHURE THE EGR ISN'T LEAKING EXAUST GAS INTO YOUR ENGINE AT IDLE SPEED.ALSO IT HELPS TO CLEAN THE EGR PISTON WHILE IT IS OPEN, SO YOU GET THE CARBON OFF THE VALVE SEAT, ANOTHER USE FOR A VACUUM PUMP, WHICH IS A VERY HANDY TOOL TO HAVE ANYHOW, BLEEDING BRAKES,ETC..I ALSO DISCOVERED TODAY THAT TPS VOLTAGE HAS A DIRECT RELATION TO EGR FUNCTION (WHILE DRIVING WITH THE VAC. GUAGE IN MY HAND) THE CLOSER I GOT TO .9 VOLTS AS OPPOSED TO THE POPULAR .98 TO .99 VOLTS, THE MORE VACUUM I GOT TO THE EGR. I AM ONLY TALKING ABOUT 1 TO 1.5 INCHES OF VACUUM DIFFERENCE HERE,BUT IF YOU TEST YOUR EGR WITH THE PUMP YOU WILL SEE IT IS ALOT. LET ME KNOW HOW YOU MAKE OUT.