P0398
Fix within a few daysCamshaft Position Sensor 'B' Circuit Intermittent/Erratic (Bank 2)
Code P0398 means your Bank 2 exhaust camshaft position sensor signal is erratic. Common causes: Bad cam sensor (70%), wiring issues (20%). Drivability: Limit driving, fix within a few days. Repair cost: $50-$150 DIY, $150-$450 professional.
Can I Drive With P0398?
Limit driving, fix within a few days
Essential trips under 10 miles, avoid highways and heavy acceleration. Be prepared for potential stalling.
Stop driving immediately if: Flashing Check Engine Light, engine stalls repeatedly, significant power loss, or loud engine noises.
Symptoms of P0398
- 1Check Engine Light is on
- 2Engine cranks but won't start
- 3Engine stalls unexpectedly
- 4Rough idle or poor engine performance
- 5Reduced engine power
- 6Poor fuel economy
- 7Engine misfires
Common Causes of P0398
Parts most likely causing this code, ranked by probability
The sensor itself has failed and is sending an inconsistent or incorrect signal to the engine computer.
70% of P0398 cases are fixed by replacing this part
Damaged wires, corroded terminals, or a loose connection prevent the sensor's signal from reaching the engine computer reliably.
20% of P0398 cases are fixed by repairing wiring or connectors
If the timing chain or belt is stretched or has jumped a tooth, the camshaft position will not match the crankshaft position, causing an erratic signal.
8% of P0398 cases are fixed by addressing timing issues
A faulty engine computer can misinterpret the sensor signal or fail to process it correctly, though this is a very rare cause.
2% of P0398 cases are fixed by replacing the ECM/PCM
Check These First (Before Buying Parts)
- Visually inspect the camshaft position sensor (Bank 2, Sensor B) and its wiring harness for any obvious damage, fraying, or loose connections.
- Ensure the sensor connector is fully seated and free of corrosion. Disconnect and reconnect it to ensure a good connection.
How to Diagnose P0398
- 1Connect an OBD-II scanner to confirm P0398 and check for other related codes.
- 2Visually inspect the camshaft position sensor (Bank 2, Sensor B) and its wiring harness for any obvious damage, fraying, or corrosion.
- 3Disconnect the sensor connector and check for bent pins or corrosion. Clean if necessary.
- 4Test the camshaft position sensor's resistance and voltage output using a multimeter, following your vehicle's service manual specifications.
- 5If possible, use a scan tool with live data to monitor the camshaft position sensor signal while cranking or running the engine.
- 6If the sensor tests good and wiring is intact, inspect the timing chain/belt for proper tension and alignment.
P0398 on Popular Vehicles
Nissan
2003-2024Many Nissan V6 engines (e.g., Maxima, Altima, Murano, 350Z, 370Z) are prone to camshaft position sensor failures, often leading to P0340, P0345, P0365, P0390, or P0398. The sensors can fail intermittently before completely failing.
75% fixed by replacing the camshaft position sensor
Infiniti
2003-2024Similar to Nissan, Infiniti models with VQ-series V6 engines (e.g., G35, G37, FX35, M35) frequently experience camshaft position sensor issues. P0398 is a common code for the exhaust cam sensor on Bank 2.
75% fixed by replacing the camshaft position sensor
Honda Accord
2003-2024On V6 Honda Accord models, camshaft position sensor failures are less common than on Nissan/Infiniti, but still occur. Wiring integrity should be thoroughly checked before replacing the sensor.
60% fixed by replacing the camshaft position sensor
Frequently Asked Questions
What does P0398 mean?
P0398 indicates that the engine computer is receiving an intermittent or erratic signal from the 'B' camshaft position sensor on Bank 2. 'Sensor B' typically refers to the exhaust camshaft sensor, and 'Bank 2' is the side of the engine without cylinder #1.
Can I drive with P0398?
Limit driving, fix within a few days. While your car might still run, an erratic camshaft signal can cause stalling, misfires, and reduced power. Continued driving with misfires can damage your catalytic converter.
Will P0398 clear itself?
No, P0398 will not clear itself. The underlying issue causing the erratic signal needs to be diagnosed and repaired. Once fixed, you can clear the code with an OBD-II scanner, or it will clear after several drive cycles if the problem is resolved.
How do I fix P0398 myself?
Start by inspecting the camshaft position sensor (Bank 2, Sensor B) and its wiring for damage. If the wiring is good, replace the camshaft position sensor. If the code persists, further diagnosis of the wiring or timing components is necessary.
How much does it cost to fix P0398?
A DIY fix for P0398, typically involving a new camshaft position sensor, costs $50-$150 for the part. If you take it to a shop, expect to pay $150-$450, which includes parts and 1-2 hours of labor.
P0398 keeps coming back - why?
If P0398 keeps returning, the initial repair likely didn't address the root cause. This often means the issue is not the sensor itself but rather damaged wiring, a faulty connector, or a more serious underlying problem like a stretched timing chain or a rare ECM fault.
Will P0398 fail emissions/smog test?
Yes, P0398 will cause your vehicle to fail an emissions or smog test. The Check Engine Light being on is an automatic failure, and an erratic camshaft signal can also lead to increased emissions.
What's the difference between P0398 and P0345?
P0398 specifically refers to an intermittent or erratic signal from the 'B' (exhaust) camshaft position sensor on Bank 2. P0345 refers to a general circuit malfunction for the 'A' (intake) camshaft position sensor on Bank 2. They both point to Bank 2 cam sensor issues but specify different sensors or types of faults.
P0398 on Nissan/Infiniti V6 engines
Nissan and Infiniti V6 engines (like the VQ35DE or VQ37VHR) are known for camshaft position sensor failures. If you have a P0398 on these vehicles, replacing the Bank 2 exhaust camshaft position sensor is a very common and effective fix.
Questions to Ask Your Mechanic
Did you check the live data for the Bank 2 exhaust camshaft position sensor signal?
Good answer: Yes, the live data showed an erratic signal that dropped out at certain RPMs, confirming the sensor is failing.
What did you find when inspecting the wiring and connector for the sensor?
Good answer: I found no visible damage to the wiring, and the connector pins were clean and tight, ruling out a simple electrical connection issue.
Repair Cost Estimate
DIY Repair
Parts only
$50-$150
Shop Repair
Parts + labor
$150-$450
Save $100-$300 by doing it yourself
Difficulty
intermediate
Time
1-2 hours
Intermediate - requires basic hand tools and an OBD-II scanner. Access to the sensor can be challenging on some vehicles, and electrical diagnosis might require a multimeter.
Cost of Waiting
Ignoring P0398 can lead to severe drivability issues like stalling or misfires. Continued misfires send unburned fuel into your exhaust, which can rapidly overheat and destroy your catalytic converter. A $50-$150 sensor job now prevents a $800-$2,500 converter replacement later.
While You're In There...
Applying dielectric grease to the electrical connector helps prevent corrosion and ensures a good electrical connection, protecting your new sensor.
Some camshaft position sensors rely on clean engine oil for proper operation (VVT systems). Ensuring fresh, clean oil is always good practice and can sometimes resolve intermittent issues.
Tools You'll Need
- OBD-II scanner
- Basic socket set
- Wrench set
- Multimeter (for diagnostics)
- Dielectric grease
P0398 is a common sensor code. Most repairs involve replacing a relatively inexpensive part, and your engine will run smoothly and reliably afterward.
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Your Next Steps
Step 1: Visually inspect the Bank 2 exhaust camshaft position sensor and its wiring. Look for any cuts, frays, or loose connections. Clean the connector with electrical contact cleaner if you see corrosion.
Step 2: If the wiring looks good, replace the Bank 2 exhaust camshaft position sensor. This is the most common fix for P0398.
Step 3: After replacing the sensor, clear the code with your OBD-II scanner and drive the vehicle to confirm the repair. If the code returns, you'll need to perform more in-depth electrical diagnostics on the wiring or consider timing system inspection.