AutoCodes – Honda – P2187 Honda

P2187 Honda Code - Fuel System Too Lean at Idle

Quick Answer

The Powertrain Control Module (PCM) detects the oxygen content in the exhaust gas from the air/fuel ratio (A/F) sensor (sensor 1) signal voltage, and it uses fuel feedback control to maintain the optimal air/fuel ratio. Common causes include Faulty fuel pump, Faulty fuel injector, Faulty fuel pressure regulator. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P2187 Honda indicates Fuel System Too Lean at Idle.
Common causes: Common causes include Faulty fuel pump, Faulty fuel injector, Faulty fuel pressure regulator.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 3,916

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Oct 18, 2021

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2187 Honda Description

The Powertrain Control Module (PCM) detects the oxygen content in the exhaust gas from the air/fuel ratio (A/F) sensor (sensor 1) signal voltage, and it uses fuel feedback control to maintain the optimal air/fuel ratio. The air/fuel ratio coefficient for correcting the amount of injected fuel is the short-term fuel trim. The PCM varies short-term fuel trim continuously to keep the air/fuel ratio close to the stoichiometric ratio for all driving conditions. In case the breather pipe is disconnected, the air amount at the mass airflow (MAF) sensor decreases, and the basic fuel amount decrease; as a result, the fuel injection quantity correction coefficient becomes larger to compensate for the gap. This condition could be seen prominently at low load which the intake air amount is small. The detection of breather pipe disconnection is done by monitoring the gap which is determined by fuel injection quantity correction coefficient average during idle and continuously updating fuel injection quantity correction coefficient. If the fuel injection quantity correction coefficient exceeds a threshold value, the PCM detects a malfunction and stores a Diagnostic Trouble Code (DTC). The purge is stopped by the fuel injection quantity correction coefficient to exclude the influence of purging during the detection.

OBDII Code P2187 Honda - Fuel System Too Lean at Idle - AutoCodes.com — P2187 Honda Code - Fuel System Too Lean at Idle

What does this mean?

What are the Possible Causes of the DTC P2187 Honda?

Faulty fuel pump
Faulty fuel injector
Faulty fuel pressure regulator
Faulty fuel line
Faulty fuel supply system
MAF sensor range/performance problem
Manifold absolute pressure (MAP) sensor range/performance problem
Faulty A/F Sensor (Sensor 1)
Faulty Secondary HO2S (Sensor 2)

How to Fix the DTC P2187 Honda?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2187 Honda code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Need more information on how to fix the P2187 Honda code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P2187 Honda code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P2187 Honda Code

1. What are the common symptoms of OBDII code P2187 in a Honda related to the fuel system being too lean at idle?

- Common symptoms include rough idle, engine hesitation, decreased fuel efficiency, and potential stalling at idle.

2. What are the possible causes of OBDII code P2187 indicating a lean fuel system at idle in a Honda?

- Causes may include a vacuum leak, faulty oxygen sensor, clogged fuel injectors, a weak fuel pump, or a malfunctioning mass airflow sensor.

3. How can a vacuum leak contribute to the OBDII code P2187 in a Honda?

- A vacuum leak can introduce excess air into the engine, causing the air/fuel mixture to become too lean, triggering the P2187 code.

4. What are some repair tips for addressing the OBDII code P2187 on a Honda due to a lean fuel system at idle?

- Inspect and repair any vacuum leaks, clean or replace clogged fuel injectors, test and replace a faulty oxygen sensor, and ensure the fuel pump is functioning correctly.

5. Can a dirty or faulty mass airflow sensor cause the OBDII code P2187 in a Honda?

- Yes, a dirty or faulty mass airflow sensor can inaccurately measure the amount of air entering the engine, leading to a lean fuel mixture and triggering the P2187 code.

6. How important is it to address the OBDII code P2187 indicating a lean fuel system at idle in a Honda promptly?

- It is crucial to address this issue promptly to prevent potential engine damage, poor performance, decreased fuel efficiency, and other related problems.

7. Are there any DIY methods to troubleshoot the OBDII code P2187 related to a lean fuel system at idle in a Honda?

- DIY methods may include visually inspecting for vacuum leaks, cleaning the mass airflow sensor, and checking for any obvious signs of fuel system issues.

8. Can a failing fuel pump be a common cause of the OBDII code P2187 in a Honda?

- Yes, a failing fuel pump that cannot deliver enough fuel to the engine can lead to a lean fuel mixture at idle, triggering the P2187 code.

9. Is it safe to continue driving a Honda with the OBDII code P2187 indicating a lean fuel system at idle?

- It is not recommended to drive the vehicle extensively with this code present, as it can lead to decreased engine performance and potential long-term damage if left unresolved.

10. How can a professional mechanic diagnose and repair the OBDII code P2187 related to a lean fuel system at idle in a Honda?

- A professional mechanic can use specialized diagnostic equipment to pinpoint the exact cause of the lean condition, such as performing a smoke test to identify vacuum leaks, testing fuel pressure, and inspecting sensor readings.