1. What is P0301 in Toyota Camry?

P0301 is a specific diagnostic trouble code indicating a cylinder 1 misfire in your Toyota Camry. This means the first cylinder in your Camry's engine isn't firing properly, disrupting combustion and reducing performance.

Camry 2.5L Engine Specifics

In 2018-2023 Camry models with the 2.5L A25A-FKS engine, cylinder 1 is located closest to the front of the vehicle (driver's side). This code often appears between 60,000-80,000 miles—a common pattern in Toyota's direct-injection engines due to increased ignition system stress.

2. Common Causes of P0301 in 2018-2023 Camry

Based on Camry owner reports and Toyota service data, these are the most frequent causes of P0301 in 2018-2023 models:

• Faulty Ignition Coil — Example: 2020 Camry with 72,000 miles developed P0301. Testing showed cylinder 1 coil resistance out of spec (should be 0.5-1.0Ω primary, 10-15kΩ secondary). Replacing with Denso 90919-C2007 coil resolved it.
• Worn Spark Plugs — Example: 2019 Camry missed 60k service; iridium plugs in cylinder 1 had excessive gap (0.055" vs spec 0.043"). New Toyota 90919-C2005 plugs fixed misfire.
• Clogged Fuel Injector — Example: 2018 Camry with P0301 had restricted injector on cylinder 1 (common with low-quality fuel). Ultrasonic cleaning restored proper flow.
• Intake Manifold Gasket Leak — Example: 2021 Camry showed P0301 after cold weather. Smoke test revealed vacuum leak near cylinder 1 port; new gasket set (04111-0V040) fixed it.
• Valve Cover Gasket Oil Leak — Example: 2022 Camry with 45k miles had oil fouling cylinder 1 plug due to leaking valve cover gasket—common Camry issue affecting ignition.

3. Symptoms of Cylinder 1 Misfire in Camry

Camry owners typically notice these specific symptoms when P0301 is present:

• Rough idle, especially noticeable when stopped at traffic lights
• Check Engine Light flashing during acceleration (critical misfire condition)
• Reduced power when accelerating from stop—common complaint in Camry's with this code
• Increased fuel consumption (1-3 MPG drop reported by owners)
• Engine vibration felt through steering wheel and pedals
• Specific to Camry: "Check Engine" + "VSC" lights often illuminate together

4. How to Diagnose P0301 with UR800

Follow this Camry-specific process using the iCarzone UR800 to pinpoint P0301 causes:

Example: A 2020 Camry with P0301 passed compression tests. The UR800 showed high misfire counts only under load. Coil swap test moved the misfire to cylinder 2, confirming a faulty ignition coil—common failure point in this model.

5. DIY Fixes for Camry P0301

• Replace Ignition Coil: Use OEM Denso 90919-C2007 (Camry-specific) — always replace as set if over 60k miles.
• Install New Spark Plugs: Toyota-recommended iridium plugs (90919-C2005) gapped to 0.043"; torque to 13 ft-lbs.
• Clean/Replace Fuel Injectors: Ultrasonic cleaning for minor clogs; replace with Denso 23250-0V020 for severe cases.
• Replace Intake Gasket: Use Toyota 04111-0V040 gasket set; common fix for 2018-2020 Camry 2.5L models.
• Valve Cover Gasket Service: Address oil leaks with 11213-0V030 gasket kit to prevent plug fouling.

Camry Optimization Tips

1. After repairs, use UR800 to perform "Idle Learn Reset" for Camry's ECU to recalibrate.
2. Always use Top Tier detergent gasoline to prevent injector clogs in direct-injection engines.
3. Torque spark plugs to exact specification—over-tightening strips Camry's aluminum cylinder head.

6. Repair Costs & Safety Tips

• Ignition Coil (OEM): $45–$75 each (Camry set of 4: $150–$250)
• Spark Plugs (set): $30–$60 (Toyota iridium)
• Fuel Injector Cleaning: $80–$150
• Intake Gasket Replacement: $150–$300 (parts + labor)
• Valve Cover Gasket Service: $200–$400

Safety Precautions

• Disconnect Camry's battery before working on ignition components to prevent electrical shock.
• Allow engine to cool completely—Camry's aluminum heads retain heat and can cause burns.
• Use torque wrench for spark plugs (13 ft-lbs) to avoid damaging cylinder head threads.
• Clear codes with UR800 after repairs and perform 10-minute test drive to confirm fix.

7. Preventing P0301 in Camry 2.5L

Avoid P0301 in your Camry with these proactive steps:

• Replace spark plugs at 60,000 miles (sooner than Toyota's 100k recommendation for direct injection).
• Inspect ignition coils at 80,000 miles—look for oil contamination (sign of valve cover leak).
• Use the iCarzone UR800 monthly to check for pending misfire codes before they illuminate the Check Engine Light.
• Add fuel system cleaner every 10,000 miles to prevent injector clogs in Camry's direct-injection system.
• Check for TSBs—Toyota issued TSB EG054-20 for 2018-2020 Camry misfire issues related to software.

8. Camry Owner FAQs About P0301

9. Summary & Next Steps

P0301 (cylinder 1 misfire) is a common issue in 2018-2023 Toyota Camry models, typically caused by worn ignition components, fuel injector issues, or vacuum leaks. Using the iCarzone UR800, you can accurately diagnose the root cause—often an ignition coil or spark plug in Camry's 2.5L engine. Prompt repairs restore performance and prevent catalytic converter damage.

Fix Camry P0301 with UR800

The iCarzone UR800 is optimized for Toyota diagnostics, featuring Camry-specific misfire tests and reset functions to resolve P0301 quickly. Perfect for DIY Camry owners.

Get UR800 for Camry Now