What are the common causes of P02B3?

A rich-running injector on cylinder 7. A stuck-high fuel pressure regulator. A slow oxygen sensor on cylinder 7. An exhaust leak ahead of the sensor. A leaking fuel injector seal on cylinder 7.

Read live fuel trim for cylinder 7 on a scan tool. Compare cylinder 7 trim against the other cylinders. Check fuel pressure for a high reading. Test the oxygen sensor response time. Clean or replace the cylinder 7 injector if it runs rich. Clear the code and retest.

P02B3

Cylinder 7 - Fuel Trim at Min Limit

System: Injector circuits (P code)
Lamp: Check Engine Light
Category: Powertrain - Fuel/Air Metering

What it means

P02B3 means Cylinder 7 - Fuel Trim at Min Limit.

Check these first

A rich-running injector on cylinder 7
A stuck-high fuel pressure regulator
A slow oxygen sensor on cylinder 7
An exhaust leak ahead of the sensor
A leaking fuel injector seal on cylinder 7

What to do next

Read live fuel trim for cylinder 7 on a scan tool
Compare cylinder 7 trim against the other cylinders
Check fuel pressure for a high reading
Test the oxygen sensor response time
Clean or replace the cylinder 7 injector if it runs rich
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.