P2B07: Cylinder 8 Injection Pulse Performance

What it means

The ECM detects that the injection pulse on cylinder 8 does not produce the expected combustion result. Pulse width, timing, or quantity drift compared to the bank average.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The ECM monitors how cylinder 8 responds when its injector is commanded and compares that response with the other cylinders on the bank. P2B07 indicates that cylinder 8's injection pulse performance is outside the expected range, potentially because the injector's flow has aged or fuel quality is affecting combustion.

Common causes

Most likely first.

1. Injector aged - flow characteristic drifted
2. Fuel quality affecting injection result

Symptoms

• Check-engine light may be on
• Rough idle or engine vibration
• Hesitation or reduced power

How to diagnose it

1. Capture freeze-frame data and review cylinder-specific misfire or fuel-balance readings to see whether cylinder 8 is singled out.
2. Check whether the vehicle recently received questionable or different fuel and whether symptoms followed that fill.
3. Inspect the cylinder 8 injector connector and harness for loose terminals, corrosion, chafing, or heat damage.
4. Compare cylinder 8 injector command and contribution data with other cylinders during the same operating conditions.
5. If readings still implicate cylinder 8, test its injector flow and spray against the manufacturer's specification.

Common fixes

• Correct a suspected fuel-quality problem with the vehicle's specified fuel and observe whether symptoms continue.
• Repair the cylinder 8 injector connection or wiring if inspection finds damage.
• Clean or service the cylinder 8 injector if deposits are present and it is serviceable.
• Replace the cylinder 8 injector if testing shows its performance is outside specification.

Can I keep driving?

If the light is steady and the engine is not shaking, keep any necessary trip short and avoid heavy load because ongoing poor combustion can increase emissions and damage the catalytic converter. Stop driving if the light flashes, roughness becomes severe, or power loss creates a safety risk.