P0344 — Camshaft Position Sensor A Circuit Intermittent Bank 1 or Single Sensor

What Does P0344 Mean?

P0344 is a diagnostic trouble code indicating: Camshaft Position Sensor A Circuit Intermittent Bank 1 or Single Sensor. This code relates to the ignition system system. It has been reported in NHTSA complaints across 4 different vehicle models.

Engine misfires are detected by monitoring crankshaft rotational speed variations. Each cylinder's power stroke produces a characteristic acceleration pattern. When a cylinder fails to fire, the crankshaft decelerates during that cylinder's stroke. The ECM identifies which cylinder misfired and how often. P0313-P0399 codes cover extended misfire monitoring including lean misfire detection, knock-related ignition faults, and secondary ignition monitoring. A flashing check engine light during active misfires is an emergency — raw unburned fuel enters the catalytic converter, potentially destroying it.

Symptoms of P0344

⚠️ Check engine light on (may flash during active misfire)
⚠️ Engine misfiring — rough idle, stumbling, shaking
⚠️ Loss of power during acceleration
⚠️ Increased emissions and fuel consumption
⚠️ Catalytic converter damage if ignored
⚠️ Possible engine vibration at idle

Common Causes

🔍 Worn or fouled spark plugs
🔍 Faulty ignition coil
🔍 Vacuum leak causing lean misfire
🔍 Fuel injector issue (clogged, leaking, or electrical)
🔍 Low compression (worn rings, burned valve, head gasket)
🔍 Incorrect ignition timing

P0344 Reports by Year

2023

2

2017

1

2018

1

2016

1

2010

1

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"2016 Ford Focus with 53,000 miles, driven less than 150 miles per week on average just getting back and forth to work and running errands. Check engine light came on on November 2, 2023. I got a P0344 code from my mechanic who is 5 minutes away from when the check engine light came on. He advised "
— Ford Focus owner, 11/06/2023

"JUST FILLED MY GAS TANK UP THEN AS I LEFT THE GAS STATION GOT ABOUT 1 MILE UP THE ROAD THEN WHILE SITTING AT A STOPLIGHT I TURNED THE AC ON AND IDLE DIPPED, CAR FELT LIKE IT WAS GOING TO DIE(WHICH IT DID) THEN AS I TRIED TO RE-START, CEL CAME ON AND CAR WOULD NOT START. ABOUT 2 MORE TIMES AND IT FIR"
— Ford Focus owner, 10/07/2017

"DRIVING CAR , CHECK ENGINE LIGHT CAME ON AT 5800 MILE, SCAN TOOL STATED CODE P0340 AND P0344, REPLACE CAM SENSOR. CLEAR CODES, DROVE CAR 3 DAYS 5980 MILE ,CHECK ENGINE FLASH COUPLE TIME AND STAY ON STARTED SMELL OIL AND SOUND LIKE IT WAS MISFIRING, SCAN IT AGAIN AND IT SAID CODE P0340 AND P0344, C"
— Ford Focus owner, 01/24/2018

Source: NHTSA Complaints Database

Most Reported Vehicles for P0344

Based on NHTSA owner complaint data.

#	Vehicle	Reports
1	JEEP WRANGLER
2	FORD FOCUS
3	DODGE JOURNEY
4	CHRYSLER 300

P0344 Reports by Vehicle

Detailed NHTSA complaint analysis for each vehicle model.

FORD FOCUS

3 NHTSA reports · Peak: 2016, 2017

JEEP WRANGLER

4 NHTSA reports · Peak: 2005, 2013, 2016

Diagnostic Tips

Check misfire counters in Mode 6 data — identifies which cylinder(s) are misfiring most
Swap ignition coil to another cylinder — if misfire follows, coil is bad
Check spark plugs — worn electrode, fouled with oil or carbon, cracked insulator all cause misfires
Perform compression test on affected cylinder(s) — low compression means mechanical issue

Common Mistakes to Avoid

❌ Replacing coils without checking spark plugs — a worn plug will kill a new coil
❌ Ignoring a flashing check engine light — this means severe misfire that's damaging the catalytic converter NOW
❌ Replacing ignition parts when the misfire is caused by a vacuum leak or low compression

Frequently Asked Questions

What does a flashing check engine light mean?

A flashing CEL means severe, active misfire that risks catalytic converter damage. Pull over safely and reduce engine load. Do not rev the engine. Drive gently to a repair facility or have it towed. This is the only CEL condition that warrants immediate action.

Can misfires damage my engine?

Misfires themselves don't usually damage the engine, but they can destroy the catalytic converter ($1000-$3000). Severe misfires also dilute engine oil with raw fuel, reducing lubrication. Extended misfires should always be repaired promptly.

Why does my car misfire only when cold?

Cold misfires are often caused by slightly worn spark plugs (gap too wide for cold, dense air-fuel mixture), marginal ignition coils that work fine once warm, or small vacuum leaks that are more noticeable at cold idle RPM.

What To Do Next

Possible Fixes

🔧 Replace spark plugs
🔧 Replace ignition coil(s)
🔧 Repair vacuum leak
🔧 Clean or replace fuel injector
🔧 Engine mechanical repair (valves, rings, gasket)

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P0344: Camshaft Position Sensor A Circuit Intermittent Bank 1 or Single Sensor