Answer A is wrong. Burning coolant emits white gray smoke from the tailpipe.

Answer B is correct. Burning oil emits blue gray smoke from the tailpipe.

Answer C is wrong. Technician B is correct.

Answer D is wrong. Technician B is correct.

Answer A is wrong. The engine coolant temperature ECT sensor input is used for idle speed calculations.

Answer B is correct. The exhaust gas recirculating EGR valve is a component that recirculates exhaust. The PCM is using fuel mixture sensors to calculate engine idle speed. The EGR valve is tasked with keeping the cylinders cool preventing harmful NOx gases from being formed.

Answer C is wrong. The IAT sensor input is used for idle speed calculations.

Answer D is wrong. The TPS is used for idle speed calculations.

Answer A is correct. This type of fan operates with a silicon type fluid not electricity. A loss of fluid will inhibit the fans operation.

Answer B is wrong. Technician A is correct. Relays are used in electric fan circuits.

Answer C is wrong. Technician A is correct.

Answer D is wrong. Technician A is correct.

Answer A is wrong. A poor ground or power condition would result in low fuel pressure.

Answer B is correct. This is an except type question. A restricted fuel return line would increase fuel pressure.

Answer C is wrong. A restricted or clogged fuel filter would result in low fuel pressure.

Answer D is wrong. A faulty or defective fuel pump would result in low fuel pressure.

Answer A is wrong. This indicates a lean condition. Less than .45 is lean and more than .45 is rich.

Answer B is correct. A powertrain control module PCM use the oxygen sensors signal in closed loop.

Answer C is wrong. Technician B is correct.

Answer D is wrong. Technician B is correct.