P CODES (POWERTRAIN) P1800 - P1899 Questions

I Have To Pass Emissions Inspection But Code P1800 Had Came Up. The Mechanic Cleared The Code And Now It Came Up Again But It Is Pending. My...

I Keep Getting These Two Codes P0420, And P1800. I Can Clear The Codes And They Will Stay Off For About A Week Or Two Then They Come Back. I...

I Have The Car Listed Above Se (bought It Used About 1 Month Ago) With About 145,00 Miles On It. The Other Day It Started Misfiring Really...