P0141 Code: Honda Accord (2018-2023) - Causes, Symptoms & Fixes

P0141 Diagnostic Guide for 2018-2023 Honda Accord

Important data note

• OWNER COMPLAINTS: No NHTSA complaints found for this make/model/year/issue combination.
• RECALLS: No recalls found in NHTSA database.
• Data limitations: The provided NHTSA data shows no recorded complaints or recalls for P0141 on the 2018-2023 Accord in the cited dataset. This guide uses general OBD-II knowledge and Honda-specific practice to help diagnose and repair P0141, while clearly noting where data is limited.

CODE MEANING AND SEVERITY

• What P0141 means: P0141 is an OBD-II diagnostic trouble code indicating an O2 sensor heater circuit malfunction. In practical terms, the heated oxygen sensor (HO2S) is not heating properly, or the heater circuit is shorted/open, preventing the sensor from reaching its optimal operating temperature quickly. This can delay correct exhaust gas measurements and fuel-trim adjustments.

• Which sensor is involved on a 2018-2023 Honda Accord: In 4-cylinder Accords (the most common configuration in this model year range), P0141 generally refers to the downstream oxygen sensor (the Bank 1 Sensor 2 or equivalent, i.e., the sensor located after the catalytic converter). On V6 variants (less common in these model years), the bank/sensor numbering differs, but the underlying issue remains: heater circuit fault in the downstream O2 sensor. For practical purposes, treat P0141 on these Accords as a heater circuit fault for the downstream O2 sensor.

• Severity and impact:

  • MIL (check engine light) is usually illuminated.
  • ECU may retard/limit fueling adjustments due to delayed sensor heating, which can affect fuel economy, emission readiness, and catalyst monitoring.
  • It is typically not an immediate “drive-then-break” failure, but unresolved P0141 can lead to longer warm-up times, reduced catalyst monitoring reliability, and potential emissions issues.
  • No recall data is indicated in the provided dataset, and there are no reported complaints for this specific combination, which means this DTC is typically diagnosed and repaired at the consumer or shop level rather than through a recall.

COMMON CAUSES ON HONDA ACCORD

• Faulty downstream O2 sensor heater element (sensor itself is bad or has failed heater).

• Damaged or corroded wiring harness for the downstream O2 sensor heater circuit (pin/connector damage, abrasion near the exhaust, exposure to heat, or water ingress).

• Faulty or blown fuse/relay related to the O2 sensor heater circuit (power supply or control circuit).

• Poor electrical ground for the heater circuit (ground path open or high resistance).

• Short to voltage or short to ground in the heater circuit due to damaged insulation.

• Exhaust leaks or sensor contamination leading to erroneous readings (less common as a cause of P0141 itself, but can complicate diagnosis).

• PCM/ECU fault (rare). In practice, most P0141 repairs involve the sensor, wiring, or fuse rather than a PCM replacement.

Note: Because the oxygen sensor heater is designed to bring the sensor to the operating temperature quickly, any fault in the heater circuit can delay the sensor’s response, which in turn can cause incorrect fuel trims and catalyst monitoring behavior.

SYMPTOMS

• Check Engine Light (MIL) illuminated with P0141 stored.

• Possible slight loss of fuel economy or inconsistent fuel trims as the sensor heats up more slowly than designed.

• Initially, the engine may run normally after startup once the sensor heats up, but the ECU may log fuel trim or catalyst-related DTCs if the sensor remains slow to heat.

• In some cases, you may notice no obvious symptoms beyond the MIL, especially if other faults aren’t present.

• Noises, rough idle, or misfire symptoms are unlikely to be directly caused by a heater circuit fault alone, though prolonged issues can contribute to drivability concerns if multiple sensors are affected.

DIAGNOSTIC STEPS

Begin with a methodical, repeatable test to isolate the heater circuit fault from a sensor or harness problem.

A. Preparation and verification

• Use a reliable OBD-II scanner to confirm P0141 and note any freeze-frame data, MIL status, and any related codes (e.g., P013x series, P0140-P0143, etc.).
• Check for any other related codes that might indicate broader exhaust or engine issues.
• Ensure the vehicle is parked safely, the engine is cool before any inspection, and you have the service manual or electrical schematic for the downstream O2 sensor circuit.

B. Visual inspection

• Inspect the downstream O2 sensor (the sensor after the catalytic converter) and its wiring harness and connectors.
• Look for damaged insulation, missing/melted heat shielding, exposed wires, corrosion on pins, or loose connectors.
• Check for oil/wear contamination on the sensor or connector that could affect heater operation.

C. verify fuse, power, and ground

• Locate the O2 sensor heater circuit fuse(s) and verify they are intact. Replace if blown.
• With the ignition ON (engine OFF), back-probe the heater circuit pins to verify presence of 12V supply to the heater circuit (or as specified by Honda service data).
• Verify a solid ground reference for the heater circuit. A poor ground can mimic a heater circuit fault.
• If the fuse, power, and ground look good, proceed to inspect the sensor heater resistance.

D. Measure heater resistance (sensor itself)

• Disconnect the sensor’s electrical connector.
• Using the DMM (digital multimeter), measure the resistance across the heater circuit pins of the O2 sensor (per Honda service data for the exact pins and expected range).
• Typical heater resistance for many sensors is in the tens of ohms range (e.g., roughly 5–60 ohms depending on sensor model). If the reading is open (very high) or shorted (very low, near zero), the sensor heater element or sensor wiring is likely defective.
• If resistance is within the expected spec, the issue might be wiring or PCM control rather than the heater element itself.

E. Check continuity and shorts in wiring

• With the sensor disconnected, test continuity from the sensor harness connector to the ECM/PCM connector for the heater circuit wires.
• Look for shorts to ground or to supply voltage along the length of harness. Any abnormal readings may indicate damaged insulation or pin corrosion.

F. Sensor operation test (if equipment available)

• Some diagnostic tools can monitor O2 sensor heater current or use live data to show when the heater is active and how quickly it heats to operating temperature.
• Monitor the sensor reading as the engine warms up. If the sensor never heats or stays out of range, the heater circuit or sensor is suspect.

G. If the heater circuit tests pass, but P0141 persists

• Remove and reinstall the sensor (or swap with a known-good unit if available) to rule out a defective sensor.
• Clear codes and perform a drive cycle to recheck. The ECU may re-check the heater circuit during the next drive cycle.
• If P0141 returns, inspect the wiring harness in more detail for hidden damage or consider PCM-related issues as a last resort.

H. Final steps

• If the downstream O2 sensor heater circuit tests are negative for faults in the sensor and wiring, but P0141 remains, consult Honda service data for any model-specific diagnostic steps, including possible software/ECU updates or controlled tests. In some cases, a software update or reflash may be recommended by the dealer if a known condition exists.

Tips during diagnostics

• Always perform safety precautions around the exhaust system; the area around the sensor is hot if recently driven.
• When disconnecting sensors, avoid damaging sensor threads or the sensor’s wiring harness.
• If you replace the O2 sensor, follow the manufacturer’s torque specification and apply anti-seize only if specified by the sensor’s instructions (some sensors have anti-seize pre-applied; do not apply anti-seize to certain sensors that specify not to).
• After completing repairs or sensor replacement, clear the codes and perform a proper drive cycle to verify the fix.

RELATED CODES

• P0140 – O2 Sensor Heater Circuit Malfunction (general reference)
• P013x family – O2 sensor circuit faults (upstream sensors)
• P0142 / P0143 – Additional downstream O2 sensor heater circuit codes in some vehicles
  Note: These related codes point to similar heater circuit or sensor issues. Diagnosis should consider a broad view of the O2 sensor circuits and catalytic monitoring.

REPAIR OPTIONS AND COSTS (2025 PRICES)

Prices vary by region, shop, and whether OEM or aftermarket parts are used. The figures below are typical retail estimates you might expect in 2025. Always get a written estimate before work.

• Downstream O2 sensor replacement (Bank 1 Sensor 2 or equivalent for 4-cylinder Accord)

  • Parts: Aftermarket sensor typically $40–$140; OEM/Dealer sensor often $120–$260.
  • Labor: Roughly 0.3–1.0 hour depending on access and vehicle variant; shop rate commonly $90–$150/hour.
  • Estimated total: $80–$300 (aftermarket parts); $180–$520 (OEM parts).

• Wiring harness or connector repair (if damaged)

  • Parts: Often minimal if repairing a damaged connector or pigtail; $0–$60 for a repair connector, plus any harness segment if replacement is needed.
  • Labor: 0.5–1.5 hours depending on accessibility and routing.
  • Estimated total: $100–$350 (labor + small parts). More extensive harness work could go higher.

• Fuse/relay replacement (simple electrical fix)

  • Parts: $5–$20 for a fuse; negligible labor if diagnosed.
  • Estimated total: $10–$60.

• PCM/ECU replacement or reflashing (rare)

  • Parts: $200–$600 for a reflashed module or a few hundred to over $1,000 for a whole replacement.
  • Labor: 1–3 hours plus typical diagnostic time.
  • Estimated total: $300–$1,600 or more, depending on vehicle and dealership pricing.

• Cat converter or catalyst-related issues (if misinterpreted)

  • Note: P0141 is not typically a direct catalyst failure code, but downstream O2 sensor performance can affect catalyst monitoring. If a catalytic issue is suspected, the cost and scope can become significantly larger (often $1,000–$3,000 or more for replacement).

DIY VS PROFESSIONAL

• DIY suitability

  • Moderate mechanical ability helps. Replacing a downstream O2 sensor is a common DIY task on many cars, including the Honda Accord, due to straightforward access on many models.
  • You should be comfortable with safely elevating the vehicle, locating the sensor, disconnecting wiring, and using an O2 sensor socket.
  • Pros: Lower cost if successful; quick turnaround.
  • Cons: If you misdiagnose and replace the wrong sensor or fail to address wiring, the code will return. Risk of stripping sensor threads if overtightened.

• When to go professional

  • If the diagnostic data is inconclusive (e.g., heater circuit resistance within spec but code persists), or if wiring harness damage is suspected in hard-to-reach areas.
  • If you do not have the right tools (O2 sensor socket, multimeter, or a capable scan tool with live data), or if you are uncomfortable handling the exhaust system.
  • If the vehicle is under warranty or you want OEM parts and dealer expertise.

• DIY steps if you choose to proceed

  • Obtain the correct downstream O2 sensor for your exact Accord engine model (4-cylinder variants use Bank 1 Sensor 2; verify with VIN or service data).
  • Gather tools: O2 sensor socket, basic hand tools, a multimeter, a way to safely lift the vehicle, and safety gear.
  • If replacing the sensor yourself:
    • Disconnect battery as a safety precaution (to avoid any ECM misbehavior while unplugging electrical connectors).
    • Locate and disconnect the O2 sensor connector. Remove the sensor from the exhaust using anti-seize or as per the sensor’s instructions.
    • Install the new sensor to the specified torque. Reconnect the electrical connector.
    • Reconnect the battery and clear codes using a scan tool.
  • After replacement, perform a proper drive cycle to confirm P0141 is cleared and not reoccurring.

• Note on warranties: If under manufacturer warranty, parts and labor are typically covered; otherwise, warranty terms vary by retailer and region.

PREVENTION

• Use high-quality sensors and components: Choose OEM or reputable aftermarket O2 sensors designed for your Honda Accord model.

• Regular inspection of wiring: Periodically inspect the O2 sensor harnesses for wear, heat damage, or corrosion around the exhaust area. Address damaged harnesses promptly to avoid intermittent faults.

• Protect against exhaust leaks: Exhaust leaks upstream or near the sensor can affect sensor readings and catalyst monitoring; repair leaks promptly to maintain accurate sensor data.

• Avoid contamination of sensors: Avoid oil, coolant, or fuel contaminants reaching sensors due to engine leaks or gasket failures.

• Maintenance of emissions system: Keep the catalytic converter and exhaust system in good condition; catalytic inefficiency can complicate O2 sensor behavior.

• Routine software updates: If Honda issues any service bulletins or software updates relating to sensor behavior, apply them via dealership service.

• Drive cycles: Regularly drive the vehicle on a mix of highway and city driving to ensure the O2 sensor systems cycle through their expected states and that the catalyst monitor becomes active.

Summary

• P0141 on a 2018-2023 Honda Accord generally indicates a O2 sensor heater circuit malfunction for the downstream sensor (Bank 1 Sensor 2 on inline-4 engines). The fault commonly stems from a bad sensor heater element, wiring/connectors, or a blown fuse/ground issue. In many cases, replacing the downstream O2 sensor resolves the code; however, if the issue is wiring or ECU-related, more extensive diagnostics may be necessary.

• There were no recalls or owner complaints in the provided data for this specific code and model year range, so no recalls should be assumed. If you are facing P0141, use a systematic diagnostic approach: verify the heater circuit's resistance, power, and ground; inspect wiring; test the sensor; and replace the sensor if needed. After repairs, clear codes and perform a drive cycle to confirm the fix.

If you’d like, I can tailor these steps to your exact Accord variant (1.5T, 2.0T, or hybrid) and walk you through a step-by-step diagnostic checklist with the appropriate pinouts and resistance ranges from Honda’s service data.