DR-22A EGR Vacuum Supply From Throttle Body

1. Disconnect throttle body to EGR back pressure valve vacuum line at the valve.
2. Connect a vacuum gauge to the disconnected line, then start the engine and raise engine speed to 2000 RPM.
3. If vacuum gauge indicates at least 5 inches of vacuum, note reading and proceed to step B.
4. If vacuum gauge indicates vacuum is below five inches, repair vacuum supply from throttle body.