Hey guys I finaly found my problem with the EGR valve on my 2000 Impala I had taken it to another garage and they analyzed and it came up with a EGR insaficent air flow after I replaced the EGR valve again then I took it apart again and started to clean it out meaning the tube that goes to the exhaust manifold and that was clear took the EGR valve off and tried to clean the passageway in the manifold and I took off the thottle body to clean behind that and noticed that it looked like a valcano behind their and had to dig it out with a screwdriver to clean it out and after I had gotten it clean I noticed that the casting was very ruff so I polished it a little to get it a little smother, thinking that it was collecting at that point plus it took a 90 deg turn right there to the EGR valve. Maybe this will solve my EGR valve insuficiant air flow problem. Gary