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P0172HondaHonda Platform HubMaster P0172 GuideMedium Severity

P0172 on Honda: Symptoms, Causes & DIY Fix

Official technical diagnostic wire for fault code P0172 (System Too Rich (Bank 1) - Symptoms, Causes & Step-by-Step Fix) specifically affecting Honda vehicles (Civic, Accord, CR-V, Pilot, HR-V).

DIY Parts Estimate
$30 - $280 (DIY Clean: $15)
Honda OEM Direct Fit
Shop Labor Quote
$180 – $380
Based on $115/hr labor
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0172 On Another Make:
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1. Symptoms of P0172 on Honda

When the Engine Control Module (ECM/PCM) on your Honda logs fault code P0172, drivers commonly observe:

Check Engine Light on on Honda (Civic, Accord)
Strong unburnt fuel odor from exhaust on Honda (Civic, Accord)
Black carbon soot around exhaust tip on Honda (Civic, Accord)
Rough idle and engine bogging under throttle on Honda (Civic, Accord)
Noticeable drop in MPG on Honda (Civic, Accord)

2. Most Likely Causes on Honda

Historical warranty claims and technical repair bulletins for Honda point to the following failure distribution:

55%
Faulty or leaking fuel injector (Honda OEM Part)
25%
Contaminated Mass Air Flow (MAF) sensor (Honda OEM Part)
12%
Stuck closed EVAP canister purge valve (Honda OEM Part)
8%
Excessive fuel pressure regulator failure (Honda OEM Part)

3. Step-by-Step DIY Repair Guide for Honda

01
Clean MAF Sensor and Throttle Body

Use dedicated MAF cleaner to remove carbon buildup from sensor wires. on Honda vehicles (Civic, Accord).

02
Check Short Term & Long Term Fuel Trims

Use live OBD-II scanner data; negative trims beyond -10% indicate the ECU is cutting fuel. on Honda vehicles (Civic, Accord).

03
Inspect Fuel Injector Leak-Down

Perform a fuel pressure leak-down test to identify injectors leaking raw gasoline into cylinders while parked. on Honda vehicles (Civic, Accord).

P0172 Guides by Honda Model

Select your specific Honda model below for exact OBD-II DLC port locations, wiring diagrams, and engine displacement specs:

Other Common Diagnostic Codes on Honda

Troubleshoot other high-frequency Check Engine Light fault codes reported across Honda vehicles:

4. Honda P0172 FAQs

What causes code P0172 to trigger on a Honda?

On Honda vehicles, P0172 is most frequently caused by Faulty or leaking fuel injector or Contaminated Mass Air Flow (MAF) sensor. Factory sensor degradation or wiring harness wear near the engine bay are common factors.

Can I safely drive my Honda with code P0172?

Driveable short distances, but unburnt fuel can damage catalytic converters. Given that P0172 carries a Medium severity rating on Honda vehicles, we advise performing diagnostic scanning via the OBD-II port before extended driving.

How much does it cost to fix P0172 on a Honda?

DIY replacement parts typically range between $30 - $280 (DIY Clean: $15). If serviced at an authorized Honda dealership, expect an additional $120–$250 in professional labor based on their $115/hr hourly rate.