C) Replace ignition coil cylinder 2
A vacuum leak adds unmetered air, causing the O2 sensor to see lean exhaust. The PCM adds fuel (positive LTFT). At idle, vacuum is high, so the leak affects mixture most; at higher RPM, manifold vacuum drops, so the leak’s effect lessens, reducing LTFT. A high MAF reading at idle (3.2 vs 2.5 g/s) indicates extra airflow the PCM cannot account for, confirming an unmetered air leak. A weak pump or clogged filter would affect all RPMs more evenly; restricted exhaust would cause negative trim or power loss. Question 2 – Ignition and Misfire Detection Question: A technician observes a P0302 (Cylinder 2 misfire) on a coil-on-plug engine. The misfire counter shows misfires only under load. A swapped coil with cylinder 4 moves the misfire to cylinder 4. What is the repair? ces test questions and answers for engine management
B) Vacuum leak
B) VVT solenoid stuck open
A) Replace spark plug cylinder 2 B) Replace fuel injector cylinder 2 C) Replace ignition coil cylinder 2 D) Perform compression test cylinder 2 C) Replace ignition coil cylinder 2 A vacuum