A Answer A is wrong. A stuck open PCV valve will cause a lean condition.

B Answer B is wrong. The PCV system cleans the crankcase from piston ring blow by and allows it to flow back into the intake for recombustion.

C Answer C is correct. Both technicians are correct.

D Answer D is wrong. Both technicians are correct.

A Answer A is correct. The crankshaft position sensor monitors the crankshafts speed and rotation.

B Answer B is wrong. A PM sensor has two wires and a hall-effect sensor has three wires.

C Answer C is wrong. Technician A is correct.

D Answer D is wrong. Technician A is correct.

A Answer A is wrong. The evaporative purge valve opens to allow fuel vapors to pass through the evaporative canister/fuel tank to the intake for combustion.

B Answer B is wrong. An evaporative pressure sensor is used to notify the PCM of gas tank pressure.

C Answer C is correct. Both technicians are correct.

D Answer D is wrong. Both technicians are correct.

A Answer A is correct. A rich fuel condition causes black colored smoke.

B Answer B is wrong. Worn rings cause blue gray colored smoke.

C Answer C is wrong. A blown head Gasket causes white gray smoke.

D Answer D is wrong. Leaking valve seals would produce blue gray smoke.

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

B Answer B is correct. For an oxygen sensor .45V is 14.7:1 or Stoichiometry.

C Answer C is wrong. Technician B is correct.

D Answer D is wrong. Technician B is correct.