FTC Reader Disclosure: When you purchase or register through links on our site, we may earn an affiliate commission at no extra cost to you. Read our Editorial & Advertising Policy.
P0171AcuraAcura PlatformMedium Severity

P0171 on Acura: Symptoms, Causes & DIY Fix

Official technical diagnostic wire for fault code P0171 (P0171: System Too Lean (Bank 1)) specifically affecting Acura vehicles (MDX, RDX, TLX, Integra, ZDX).

DIY Parts Estimate
$80 - $350 (DIY: $15 - $70)
Acura OEM Direct Fit
Shop Labor Quote
$180 – $380
Based on $130/hr labor
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0171 On Another Make:
ToyotaBMWMercedes-BenzLexusFordHyundaiCadillacTeslaChevroletHonda

1. Symptoms of P0171 on Acura

When the Engine Control Module (ECM/PCM) on your Acura logs fault code P0171, drivers commonly observe:

Check Engine Light on on Acura (MDX, RDX)
Rough idling or engine hesitation on acceleration on Acura (MDX, RDX)
Hard starting in cold weather on Acura (MDX, RDX)
Pinging or knocking sound under load on Acura (MDX, RDX)

2. Most Likely Causes on Acura

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

55%
Dirty or failing Mass Air Flow (MAF) sensor (Acura OEM Part)
25%
Cracked intake air boot or disconnected vacuum hose (Acura OEM Part)
12%
Clogged fuel filter or weak fuel pump (Acura OEM Part)
8%
Stuck open PCV valve or leaking intake manifold gasket (Acura OEM Part)

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

01
Clean the Mass Airflow (MAF) Sensor

Disconnect the battery, unclip the MAF sensor on the air intake tube, and spray 10-15 bursts of dedicated MAF cleaner onto the thin wire sensor. Allow to dry 15 minutes before reinstalling. on Acura vehicles (MDX, RDX).

Required Tool: CRC MAF Sensor Cleaner, Screwdriver
02
Inspect Intake Air Ducting

Check the rubber accordion hose between air filter box and throttle body for tears or dry rot cracks. on Acura vehicles (MDX, RDX).

Required Tool: Flashlight
03
Inspect PCV Valve and Hoses

Shake the PCV valve; if it doesn't rattle cleanly, replace it. Inspect attached rubber hoses for collapsing. on Acura vehicles (MDX, RDX).

Required Tool: Pliers
04
Check Fuel Pressure

Connect fuel pressure gauge to the Schrader valve on fuel rail. Verify pressure meets factory PSI specs. on Acura vehicles (MDX, RDX).

Required Tool: Fuel Pressure Tester Kit
05
Clear Codes and Reset Fuel Trims

Clear DTCs and verify Long Term Fuel Trims (LTFT) return below +/- 10% on your scanner. on Acura vehicles (MDX, RDX).

Required Tool: OBD-II Scanner

4. Acura P0171 FAQs

What causes code P0171 to trigger on a Acura?

On Acura vehicles, P0171 is most frequently caused by Dirty or failing Mass Air Flow (MAF) sensor or Cracked intake air boot or disconnected vacuum hose. Factory sensor degradation or wiring harness wear near the engine bay are common factors.

Can I safely drive my Acura with code P0171?

Yes, but prolonged lean running increases cylinder combustion temperatures. Given that P0171 carries a Medium severity rating on Acura vehicles, we advise performing diagnostic scanning via the OBD-II port before extended driving.

How much does it cost to fix P0171 on a Acura?

DIY replacement parts typically range between $80 - $350 (DIY: $15 - $70). If serviced at an authorized Acura dealership, expect an additional $120–$250 in professional labor based on their $130/hr hourly rate.