Advanced Engine Performance actual EXAM
120 QUESTIONS AND CORRECT
ANSWERS 2025 LAEST>>GRADED A+
The sensor that must be warmed up and functioning before the engine management computer will go
to closed loop is the _____ - ANSWER****O2S
The voltage output of a zirconia oxygen sensor when the exhaust stream is lean (excess oxygen) is ____.
- ANSWER****Relatively low (close to zero volts)
The two internal chambers of a dual-cell wide-band oxygen sensor include - ANSWER****Air reference
and diffusion
When the exhaust is rich, the PCM applies a ____ current into the pump cell. - ANSWER****Negative
A dual-cell wide-band oxygen sensor can be tested using a ____ - ANSWER****Scan tool
Voltmeter
Scope
If the air-fuel rations is 14.7:1, what is lambda? - ANSWER****1.0
If lambda is 0.98, this means the ______. - ANSWER****Air-fuel mixture is within 2% of stoichiometric
Air-fuel mixture is slightly rich
Base pulse width is determined by _____ - ANSWER****Computer calculations
Input from many sensors, except the oxygen sensor
The air at high altitude has ______. - ANSWER****21% oxygen
, In a speed density system, what does NOT need to be corrected for? - ANSWER****Oxygen in the
exhaust system from the oxygen snesor
In a MAF system, which is correct? - ANSWER****The amount of EGR flow must be subtracted from the
MAF sensor reading
Injector pulse width is measured in ______ - ANSWER****Milliseconds (ms)
What is NOT true about short-term fuel trim? - ANSWER****It can add and subtract a large amount of
fuel
A Nissan is being checked, using a scan tool, and Alpha is 107. This means ______ - ANSWER****The
PCM is adding fuel
A contaminated or defective MAF sensor is indicated if _____. - ANSWER****The fuel trim number
follows the airflow
Tech A says that the fuel-pump relay is usually controlled by the PCM. Tech B says that a TBI Injector
squirts fuel above the throttle plate. Who is correct? - ANSWER****Both Technicians A and B
Why are some fuel rails rectangular in shape? - ANSWER****Reduces noise
Which fuel-injection system uses the MAP sensor as the primary sensor to determine the base pulse
width? - ANSWER****Speed density
Why is a vacuum line attached to a fuel-pressure regulator on many port fuel-injected engines? -
ANSWER****To create an equal pressure drop across the injectors
Which sensor has the greatest influence on injector pulse width besides the MAF sensor? -
ANSWER****TP
120 QUESTIONS AND CORRECT
ANSWERS 2025 LAEST>>GRADED A+
The sensor that must be warmed up and functioning before the engine management computer will go
to closed loop is the _____ - ANSWER****O2S
The voltage output of a zirconia oxygen sensor when the exhaust stream is lean (excess oxygen) is ____.
- ANSWER****Relatively low (close to zero volts)
The two internal chambers of a dual-cell wide-band oxygen sensor include - ANSWER****Air reference
and diffusion
When the exhaust is rich, the PCM applies a ____ current into the pump cell. - ANSWER****Negative
A dual-cell wide-band oxygen sensor can be tested using a ____ - ANSWER****Scan tool
Voltmeter
Scope
If the air-fuel rations is 14.7:1, what is lambda? - ANSWER****1.0
If lambda is 0.98, this means the ______. - ANSWER****Air-fuel mixture is within 2% of stoichiometric
Air-fuel mixture is slightly rich
Base pulse width is determined by _____ - ANSWER****Computer calculations
Input from many sensors, except the oxygen sensor
The air at high altitude has ______. - ANSWER****21% oxygen
, In a speed density system, what does NOT need to be corrected for? - ANSWER****Oxygen in the
exhaust system from the oxygen snesor
In a MAF system, which is correct? - ANSWER****The amount of EGR flow must be subtracted from the
MAF sensor reading
Injector pulse width is measured in ______ - ANSWER****Milliseconds (ms)
What is NOT true about short-term fuel trim? - ANSWER****It can add and subtract a large amount of
fuel
A Nissan is being checked, using a scan tool, and Alpha is 107. This means ______ - ANSWER****The
PCM is adding fuel
A contaminated or defective MAF sensor is indicated if _____. - ANSWER****The fuel trim number
follows the airflow
Tech A says that the fuel-pump relay is usually controlled by the PCM. Tech B says that a TBI Injector
squirts fuel above the throttle plate. Who is correct? - ANSWER****Both Technicians A and B
Why are some fuel rails rectangular in shape? - ANSWER****Reduces noise
Which fuel-injection system uses the MAP sensor as the primary sensor to determine the base pulse
width? - ANSWER****Speed density
Why is a vacuum line attached to a fuel-pressure regulator on many port fuel-injected engines? -
ANSWER****To create an equal pressure drop across the injectors
Which sensor has the greatest influence on injector pulse width besides the MAF sensor? -
ANSWER****TP
