For 1990-2009 cars

Checks | Actions
--- | ---
DEFINITION: Engine power variation under steady throttle or cruise -- Feels like vehicle speeds up and slows down with no change in throttle position.
Misfire Counts | Check misfire counts using a scan tool (if any exist).
Torque Converter Clutch (TCC) | Verify proper TCC operation and customer understanding of TCC.
A/C Clutch | Verify proper A/C clutch operation.
Fuel Trim Values |

• | Monitor long term fuel trim values on a scan tool for system running lean (short term near or above 147).

• | Monitor long term fuel trim values on a scan tool for system running rich (short term FT near or below 101).

Exhaust Gas Recirculation (EGR) | Check EGR operation.
Generator Output Voltage | Check voltage.
Vacuum Lines | Check vacuum lines for kinks or leaks.
Fuel Pressure | Check fuel pressure.
Spark Plugs | Check spark plugs for cracks, wear, burned or heavy deposits on electrodes.
Fuel | Check fuel quality.