Engine Performance SOS/ASE EXAM QUESTIONS AND ANSWERS 100% SOLVED (Newest 2025) What are the key components in an EVAP system? - Correct Answers Fuel Tank, gas cap, lines/hoses, and charcoal canister
Catalytic Converter: - Correct Answers Oxidizes NOx into CO and HC
When testing a connector what is an acceptable reading?a.) 1V from ground side b.) 1V from positive/reference side c.) .5V from at each connector d.) 1.5v from sensor harness - Correct Answers C
An oxygen sensor is reading 400mv, what would this indicate - Correct Answers lean condition
What increases NOx emissions? - Correct Answers High combustion temperatures
You have examined a set of spark plugs and found them to have a black crusty finish on them. What does this indicate? - Correct Answers Rich air/fuel mixture
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Engine Performance SOS/ASE EXAM QUESTIONS AND ANSWERS 100% SOLVED (Newest 2025) A vehicle comes in with poor performance, low power and a flashing check engine light. What would this indicate? - Correct Answers Engine misfire
What is the function of the EGR valve? - Correct Answers to recirculate exhaust gases into the intake
Emission control systems are installed on engines to reduce what 3 specific exhaust emissions? - Correct Answers (HC) hydrocarbons, (CO) Carbon Monoxide, and Oxides of Nitrogen (NOx)
You are monitoring the TPS/APP sensor voltage reading with slow steady
acceleration should read: - Correct Answers .50v at idle to 4.5 at
WOT
If the voltage reading on one cylinder is not high enough, what is the most likely source of the problem? - Correct Answers Bad spark plug
At WOT the PCM module reverts to: - Correct Answers Open loop,
rich mixture
What are the 2 types of EVAP Leaks? - Correct Answers 0.020 small leak and 0.040 large leak
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Engine Performance SOS/ASE EXAM QUESTIONS AND ANSWERS 100% SOLVED (Newest 2025)
1.) All the following are pre-combustion emission controls except:
a.) Catalytic converter b.) PCV system c.) Timing control systems d.) EGR systems - Correct Answers A
Tech A says that HCs result from unburned fuel and from incomplete combustion.Tech B says that CO is formed with a mixture that is too rich.Which Technician is correct? - Correct Answers Both
Port injection injects fuel: - Correct Answers Injects fuel behind the
intake valve
(DI) Direct Injection: - Correct Answers Injects fuel directly into the
combustion chamber (Diesels)
What do post-combustion control systems do? - Correct Answers Cleans up exhaust gases after fuel has been burnt
What does the downstream O2 sensor do? - Correct Answers monitors catalytic converter efficiency
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