P0055
Fix within 1-2 weeksThe engine computer detects an issue with the heater circuit resistance for the oxygen sensor located after the catalytic converter on Bank 1.
Code P0055 means your Bank 1 Sensor 3 oxygen sensor's heater circuit has an issue. Common causes: Faulty O2 sensor (85%), wiring damage (10%), blown fuse (4%). Drivability: Yes, safe to drive. Repair cost: $50-$200 DIY, $150-$500 professional.
Can I Drive With P0055?
Yes, safe to drive
No restrictions
Stop driving immediately if: Flashing CEL, loud noises, burning smell, rotten egg smell, significant power loss
Symptoms of P0055
- 1Check Engine Light is on
- 2Slight decrease in fuel economy (over time)
- 3Engine may run slightly rich or lean (not usually noticeable)
Common Causes of P0055
Parts most likely causing this code, ranked by probability
The heating element inside the oxygen sensor fails, causing incorrect resistance readings.
85% of P0055 cases are fixed by replacing this part
Damaged, corroded, or loose wiring and connectors prevent proper power or ground to the sensor heater.
10% of P0055 cases are fixed by repairing wiring
A blown fuse in the circuit supplying power to the oxygen sensor heater prevents it from operating.
4% of P0055 cases are fixed by replacing a fuse
A rare internal fault in the engine computer prevents it from properly controlling the oxygen sensor heater circuit.
1% of P0055 cases are fixed by replacing the ECM/PCM
Check These First (Before Buying Parts)
- Locate and inspect the fuse for the O2 sensor heater circuit. Replace if blown.
- Visually inspect the wiring harness and connector for the Bank 1 Sensor 3 oxygen sensor for any signs of damage, fraying, or corrosion.
How to Diagnose P0055
- 1Check for any blown fuses related to O2 sensor heaters in the fuse box.
- 2Visually inspect the wiring harness and connector for the Bank 1 Sensor 3 oxygen sensor for damage, corrosion, or loose connections.
- 3Using a multimeter, test the resistance of the heater circuit terminals on the oxygen sensor itself. Compare to factory specifications.
- 4Using a multimeter, check for proper voltage and ground at the oxygen sensor connector with the ignition on.
P0055 on Popular Vehicles
Toyota Camry
2007-2024P0055 on Camry models is frequently due to the Bank 1 Sensor 3 oxygen sensor's internal heater failing. This sensor is located after the catalytic converter on the side of the engine with cylinder #1.
85% fixed by replacing the O2 sensor
Honda Accord
2003-2024Honda Accord vehicles often experience P0055 due to the downstream (post-catalytic converter) oxygen sensor heater circuit failing. Inspect the wiring carefully, as Honda harnesses can sometimes be susceptible to rodent damage.
80% fixed by replacing the O2 sensor, 15% by wiring repair
Ford F-150
2004-2024For Ford F-150 trucks, P0055 typically points to a failed Bank 1 Sensor 3 oxygen sensor. Given the exposed location of some exhaust components, check for physical damage to the sensor or its wiring from road debris.
85% fixed by replacing the O2 sensor
Frequently Asked Questions
What does P0055 mean?
P0055 indicates that the engine computer has detected a problem with the electrical resistance of the heater circuit for the oxygen sensor located after the catalytic converter on Bank 1. This sensor helps monitor the catalytic converter's efficiency.
Can I drive with P0055?
Yes, you can drive safely with a P0055 code. The vehicle will still operate, but your fuel economy might decrease slightly, and the emissions system will not function optimally. Fix this within 1-2 weeks to prevent potential long-term issues.
Will P0055 clear itself?
No, P0055 will not clear itself. The engine computer stores this code because it detects a persistent electrical fault. The Check Engine Light will remain on until the underlying issue is resolved and the code is manually cleared or the vehicle completes several drive cycles without the fault.
How do I fix P0055 myself?
Start by checking the relevant fuse for the O2 sensor heater circuit. Inspect the wiring and connector for the Bank 1 Sensor 3 oxygen sensor for any visible damage or corrosion. If those are good, replace the Bank 1 Sensor 3 oxygen sensor. You will need an O2 sensor socket and a ratchet.
How much does it cost to fix P0055?
DIY repair costs for P0055 are typically $50-$200, primarily for a new oxygen sensor. Professional repair at a shop usually costs $150-$500, which includes parts and labor.
P0055 keeps coming back - why?
If P0055 keeps returning, it indicates the initial repair did not address the root cause. This often happens if the wiring or connector damage was overlooked, if a new sensor was faulty, or if there's a rare issue with the engine computer itself. Double-check all electrical connections and test the new sensor's resistance.
Will P0055 fail emissions/smog test?
Yes, P0055 will cause your vehicle to fail an emissions or smog test. The Check Engine Light being on, regardless of the code, is an automatic failure in most jurisdictions. Additionally, the faulty O2 sensor prevents the emissions system from properly monitoring catalytic converter efficiency.
What's the difference between P0055 and P0053?
P0055 specifically refers to an issue with the *resistance* of the heater circuit for Bank 1 Sensor 3. P0053 refers to an issue with the *performance* of the heater circuit for Bank 1 Sensor 3, meaning the heater is not reaching or maintaining its target temperature efficiently. Both point to a problem with the O2 sensor heater, but P0055 is a direct electrical resistance fault.
P0055 on Toyota Camry?
On Toyota Camry models, P0055 is most commonly caused by a failed Bank 1 Sensor 3 oxygen sensor. These sensors are wear items and their heater elements can burn out over time. Always check the fuse and wiring first, but expect to replace the sensor.
Questions to Ask Your Mechanic
Did you check the fuse for the O2 sensor heater circuit?
Good answer: Yes, I confirmed the fuse is good and has proper voltage.
What was the resistance reading of the Bank 1 Sensor 3 heater circuit?
Good answer: The resistance was out of specification, indicating an internal fault in the sensor's heater element.
Did you inspect the wiring and connector for corrosion or damage?
Good answer: Yes, I thoroughly checked the harness and connector for any breaks, chafing, or corrosion, and they are in good condition.
Repair Cost Estimate
DIY Repair
Parts only
$50-$200
Shop Repair
Parts + labor
$150-$500
Save $100-$300 by doing it yourself
Difficulty
intermediate
Time
0.5-1.5 hours
Intermediate - requires basic electrical testing with a multimeter and specific tools like an O2 sensor socket, but is generally straightforward.
Cost of Waiting
Ignoring P0055 leads to reduced fuel efficiency and the engine computer cannot accurately monitor the catalytic converter. Over time, this can lead to premature failure of the catalytic converter, which is an expensive repair ($800-$2,500). A $100 sensor replacement now prevents a much larger bill later.
While You're In There...
Applying anti-seize to the new O2 sensor threads prevents it from seizing in the exhaust, making future removal easier.
If you need to remove any exhaust components to access the sensor, replacing old gaskets prevents exhaust leaks.
Tools You'll Need
- OBD-II Scan Tool
- Multimeter
- Oxygen Sensor Socket
- Ratchet and Extensions
- Wire Brush (for exhaust threads)
P0055 is a common code, and most repairs involve replacing a relatively inexpensive oxygen sensor. Your engine will run more efficiently and cleanly once fixed.
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Your Next Steps
Step 1: Check the fuse for the O2 sensor heater circuit. If blown, replace it and clear the code. If the fuse blows again, there's a short in the wiring.
Step 2: If the fuse is good, visually inspect the wiring and connector for the Bank 1 Sensor 3 oxygen sensor. Look for cuts, chafing, or corrosion. Repair any damage.
Step 3: If wiring is good, use a multimeter to test the resistance of the heater circuit on the oxygen sensor itself. If it's outside specifications (usually 2-10 ohms), replace the Bank 1 Sensor 3 oxygen sensor.