AutoCodes – Subaru – P1421 Subaru

P1421 Subaru Code - Exhaust Gas Recirculation Circuit High Input

Quick Answer

P1421 Subaru indicates Exhaust Gas Recirculation Circuit High Input. Common causes include Faulty EGR valve, EGR valve harness is open or shorted, EGR valve circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P1421 Subaru indicates Exhaust Gas Recirculation Circuit High Input.
Common causes: Common causes include Faulty EGR valve, EGR valve harness is open or shorted, EGR valve circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 3,709

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

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Table of contents Created and updated by William Orellana on Aug 22, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1421 Subaru Description

OBDII Code P1421 Subaru - Exhaust Gas Recirculation Circuit High Input - AutoCodes.com — P1421 Subaru Code - Exhaust Gas Recirculation Circuit High Input

What does this mean?

What are the Possible Causes of the DTC P1421 Subaru?

Faulty EGR valve
EGR valve harness is open or shorted
EGR valve circuit poor electrical connection

How to Fix the DTC P1421 Subaru?

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 P1421 Subaru 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.

Need more information about the P1421 Subaru code?

Need more information on how to fix the P1421 Subaru code? Get Access to Factory Service Manuals

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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 P1421 Subaru Code

1. What does the OBDII code P1421 mean on a Subaru?

P1421 indicates a high input in the Exhaust Gas Recirculation (EGR) circuit, which means the EGR system is not functioning properly or the signal is out of range.

2. What are the symptoms of code P1421 on a Subaru?

Common symptoms include a check engine light, rough idling, decreased fuel efficiency, engine hesitation, and increased nitrogen oxide (NOx) emissions.

3. What causes the P1421 code in a Subaru?

Potential causes include a faulty EGR valve, clogged EGR passages, wiring or connector issues, a failed EGR sensor, or a malfunctioning engine control module (ECM).

4. Can I keep driving my Subaru with the P1421 code?

While the car may remain drivable, ignoring the issue can lead to poor performance, reduced fuel efficiency, and potential damage to the engine or emissions system.

5. How do I diagnose the P1421 code on a Subaru?

Diagnosis involves checking the EGR valve and passages for clogs, inspecting wiring and connectors for damage or corrosion, testing the EGR sensor, and verifying ECM functionality.

6. How can I fix the P1421 code on my Subaru?

Common fixes include cleaning or replacing the EGR valve, repairing damaged wiring or connectors, replacing the EGR sensor, or updating/replacing the ECM if necessary.

7. How much does it cost to fix a P1421 code in a Subaru?

Repair costs vary, but cleaning an EGR valve may cost $100â€“$200, while replacing the valve or sensor could range from $150â€“$500 depending on parts and labor.

8. Can a clogged EGR passage cause the P1421 code?

Yes, clogged EGR passages can restrict exhaust gas flow, causing high input readings and triggering the P1421 code.

9. Will clearing the P1421 code solve the problem?

Simply clearing the code without fixing the underlying issue will not resolve the problem, and the code is likely to return.

10. Is P1421 a common problem in Subaru vehicles?

Itâ€™s not one of the most common codes but can occur in older Subaru models or vehicles with high mileage due to wear or carbon buildup in the EGR system.