ASEP 158 - Engine Performance Level 2

1. Complete general Engine Performance related Level 2 NATEF tasks as listed below.
   1. Identify and interpret engine performance concerns; determine necessary action.
   2. Research applicable vehicle and service information, vehicle service history, service precautions, and technical service bulletins.
   3. Diagnose abnormal engine noises or vibration concerns; determine necessary action.
   4. Diagnose abnormal exhaust color, odor, and sound; determine necessary action
   5. Perform engine absolute (vacuum/boost) manifold pressure tests; determine necessary action.
   6. Perform cylinder power balance test; determine necessary action.
   7. Perform cylinder cranking and running compression tests; determine necessary action.
   8. Perform cylinder leakage test; determine necessary action.
   9. Diagnose engine mechanical, electrical, electronic, fuel, and ignition concerns; determine necessary action.
   10. Verify engine operating temperature; determine necessary action.
   11. Verify correct camshaft timing.
2. Complete Level 2 NATEF tasks related to Computerized Engine Controls as listed below.
   1. Retrieve and record diagnostic trouble codes, OBD monitor status, and freeze frame data; clear codes when applicable.
   2. Access and use service information to perform step-by-step (troubleshooting) diagnosis.
   3. Perform active tests of actuators using a scan tool; determine necessary action.
   4. Describe the importance of running all OBDII monitors for repair verification.
3. Complete Level 2 NATEF tasks related to Ignition System Diagnosis and Repair as listed below.
   1. Diagnose (troubleshoot) ignition system related problems such as no-starting, hard starting, engine misfire, poor driveability, spark knock, power loss, poor mileage, and emissions concerns; determine necessary action.
   2. Inspect and test crankshaft and camshaft position sensor(s); perform necessary action.
   3. Inspect, test, and/or replace ignition control module, powertrain/engine control module; reprogram as necessary.
   4. Remove and replace spark plugs; inspect secondary ignition components for wear and damage.
4. Complete Level 2 NATEF tasks related to Fuel, Air Induction, and Exhaust Systems as listed below.
   1. Check fuel for contaminants; determine necessary action.
   2. Inspect and test fuel pumps and pump control systems for pressure, regulation, and volume; perform necessary action.
   3. Replace fuel filter(s).
   4. Inspect, service, or replace air filters, filter housings, and intake duct work.
   5. Inspect throttle body, air induction system, intake manifold and gaskets for vacuum leaks and/or unmetered air.
   6. Inspect and test fuel injectors.
   7. Verify idle control operation.
   8. Inspect integrity of the exhaust manifold, exhaust pipes, muffler(s), catalytic converter(s), resonator(s), tail pipe(s), and heat shields; perform necessary action.
   9. Inspect condition of exhaust system hangers, brackets, clamps, and heat shields; repair or replace as needed.
   10. Perform exhaust system back-pressure test; determine necessary action.
   11. Check and refill diesel exhaust fluid (DEF).
5. Complete Level 2 NATEF tasks related to Emissions Control Systems as listed below.
   1. Diagnose oil leaks, emissions, and driveability concerns caused by the positive crankcase ventilation (PCV) system; determine necessary action.
   2. Inspect, test, and service positive crankcase ventilation (PCV) filter/breather cap, valve, tubes, orifices, and hoses; perform necessary action.
   3. Diagnose emissions and driveability concerns caused by the exhaust gas recirculation (EGR) system; determine necessary action.
   4. Inspect, test, service, and replace components of the EGR system including tubing, exhaust passages, vacuum/pressure controls, filters, and hoses; perform necessary action.
   5. Inspect and test electrical/electronically-operated components and circuits of air injection systems; perform necessary action.
   6. Inspect and test catalytic converter efficiency.
   7. Inspect and