ASE A8 · Engine Performance
Emissions Control
Diagnosing emission control systems: PCV, EGR, secondary air injection and catalytic converters, and evaporative (EVAP) controls, using scan data and DTCs.
- Questions on the A8 test
- 8
- Share of the test
- 16%
- GearheadPass questions
- 34
- With exhibits
- 7
What this area covers
ASE's task list for Emissions Control on the A8 Engine Performance test groups into these tasks. Expect diagnosis-first questions: what's the most likely cause, what should be checked next, and which technician is right.
- PCV system testing and service
- EGR diagnosis and components
- Secondary air injection
- Catalytic converter diagnosis
- EVAP system testing and repair
How to study it
- This area carries 8 of the A8 test's questions (16%). Give it study time in proportion.
- Work the free questions first, then read every explanation, including the ones you got right; the reasoning is what transfers to new questions.
- 2 of the 5 free questions here are Technician A/B items. Judge each statement on its own before you pick A only, B only, Both or Neither.
- Always confirm specifications in the vehicle manufacturer's service information. Test questions assume you would.
Free practice quiz
5 Emissions Control questions with explanations
All 34 Emissions Control questions are in the app
Plus a full-length A8 mock, flash cards, and English or Spanish on every question.
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Diagnosing ignition-related no-start, misfire, knock, power loss and emissions problems, including primary and secondary circuits, coils, sensors, and ignition and engine control modules.
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Diagnosing fuel delivery, air induction and exhaust problems on port and direct injection engines: fuel trim, pumps and pressure, injectors, throttle bodies, vacuum leaks and turbochargers.
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Computerized Engine Controls
Diagnosing engine computer systems: DTCs, freeze frame and OBD II monitors, faults with or without codes, sensors and actuators, power and ground circuits, PCM programming and networks.