Poor DRIVEABILITY

Poor Idling: 

• Check coolant temperature sensor and connection.
• Check air temperature sensor and mass airflow meter.
• Check coolant temperature sensor.
• Ensure spark plugs are not fouled.
• Check ignition and sensor wires for proper connection.
• Check ignition and coil circuit.
• Check intake system.

Hesitation/Poor Acceleration: 

• Defective mass airflow sensor.
• Damaged ignition wires.
• Blocked air cleaner/air intake.
• Uneven compression.
• Low fuel pressure.
• Blocked exhaust system.
• Faulty sensor signals.
• Faulty turbocharger (if applicable).
• Wastegate valve open (if applicable).

Muffler Explosion (Backfire): 

• Ensure timing belt has not jumped.
• Check for gasoline in oil.
• Ensure fuel injectors are not leaking.
• Check ignition and coil circuit.
• Check engine speed (RPM) sensor.
• Check throttle switch and connector.
• Check exhaust system.

Engine Misfire: 

• Check fuel injectors.
• Check ignition and sensor wires for proper connection.
• Check ignition and coil circuit.
• Check for gasoline in oil.
• Check intake and exhaust system.
• Check for vacuum leaks.

Insufficient Engine Power: 

• Check fuel injectors.
• Ensure fuel pressure is correct.
• Check mass airflow sensor.
• Check for restricted exhaust.
• Check intake and exhaust system.

Poor Fuel Economy: 

• Check for leaky fuel injectors.
• Ensure spark plugs are not fouled.
• Check for faulty oxygen sensor.
• Check for poor wire connections and fouled spark plugs.

Excessive HC & NOx: 

• Check for gasoline in oil.
• Check for leaky fuel injectors.
• Check for faulty oxygen sensor.
• Check ignition and sensor wires for proper connection.
• Check engine speed sensor.
• Check intake system.