P0301 on a 2022 Toyota Camry
Cylinder 1 Misfire
What does P0301 mean on a 2022 Toyota Camry?
P0301 is set when the engine control module's misfire monitor detects that combustion is failing specifically in cylinder 1. The ECM identifies the affected cylinder by correlating crankshaft deceleration with camshaft position. The fact that only cylinder 1 is misfiring narrows the cause to parts that are specific to that cylinder — its plug, coil, injector, compression, or in some cases its harness wiring.
Symptoms on a 2022 Toyota Camry
- Check Engine Light steady or flashing depending on misfire severity
- Distinct rough idle that smooths out at higher RPM
- Stumble or hesitation under acceleration
- Reduced engine power
- Smell of unburned fuel from the exhaust
- Faint exhaust pop or backfire on overrun in severe cases
Likely causes on a 2022 Toyota Camry
- Failed ignition coil on cylinder 1 Most commonEstimated repair: $80– $450
On coil-on-plug engines this is the single most likely cause.
- Worn, fouled, or wrong-gap spark plug in cylinder 1 Most commonEstimated repair: $15– $80
- Clogged, leaking, or electrically failed injector on cylinder 1 CommonEstimated repair: $150– $800
- Burnt exhaust valve or low compression on cylinder 1 OccasionalEstimated repair: $800– $3,500
- Damaged or chafed wiring to the cylinder 1 coil or injector OccasionalEstimated repair: $80– $300
- Cracked cylinder 1 intake runner or local vacuum leak RareEstimated repair: $100– $600
How to diagnose this on a 2022 Toyota Camry
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Confirm cylinder 1 location on this engine
Cylinder 1 numbering differs by manufacturer. On most inline engines cylinder 1 is at the front. On most transverse V6s cylinder 1 is on the bank closer to the firewall. Consult the service manual before pulling parts.
Tools: Vehicle-specific service information
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Swap the cylinder 1 ignition coil with a known-good cylinder
Move the cylinder 1 coil to cylinder 2 (or any non-misfiring cylinder), and move that coil to cylinder 1. Clear codes and drive. If the misfire follows the coil to its new cylinder, replace the coil. If the misfire stays in cylinder 1, the coil is fine.
Tools: Socket set
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Swap the cylinder 1 spark plug
Use the same swap method with the spark plug. Inspect the removed plug first — a wet, fuel-soaked plug means no spark or no compression; a black sooty plug means a rich condition; a cracked ceramic means replace immediately.
Tools: Spark plug socket, Extension and ratchet
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Test the cylinder 1 injector electrically and acoustically
Listen to the injector with a stethoscope at idle — it should click rhythmically. A "noid light" or scan tool fuel-injector test confirms that the ECM is firing the injector. If it pulses but the cylinder still misfires, the injector may be clogged or leaking.
Tools: Mechanic's stethoscope, Noid light kit or scan tool injector test
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Perform a wet/dry compression test on cylinder 1
Measure compression on cylinder 1 cold and warm. If significantly lower than the other cylinders, add a teaspoon of oil through the plug hole and retest. Pressure that rises with oil points to worn rings; pressure that stays low points to valves or the head gasket.
Tools: Compression tester, Engine oil
Known Technical Service Bulletins for the 2020-2024 Toyota Camry
Manufacturers publish Technical Service Bulletins (TSBs) when a known issue affects a specific vehicle. These bulletins come from the NHTSA database for your Toyota Camry.
- ENGINE Feb 26, 2026
OBSOLETE NOTICE February 27, 2026: This bulletin is no longer applicable and is now obsolete.
NHTSA #11029896 - ELECTRICAL SYSTEM Jan 29, 2026
OBSOLETE NOTICE January 30, 2026: This bulletin is now obsolete. Please see T-SB-0001-26.
NHTSA #11028726 - ELECTRICAL SYSTEM Jan 27, 2026
Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool (SST) USB flash drive to update the map, points of interest, and system software.
NHTSA #11028722 - UNKNOWN OR OTHER Jan 6, 2026
Some 2005 – 2026 Toyota vehicles that have undergone water intrusion may exhibit a condition in which a musty odor is present. Follow the procedures in this bulletin to remediate the odor and address this condition. The purpose of this Service Bulletin is to provide general guidelines and procedures for odor remediation. This Service Bulletin provides a guide on how to prepare and treat the interior of the vehicle for odor remediation. Refer to the applicable model and model year Repair Manual and the EPA (Environmental Protection Agency) website for the most up-to-date safety and precautionary guidelines.
NHTSA #11028712 - ENGINE Aug 6, 2025
The specific condition covered by this program is for a small engine coolant leak that can occur from the flow shut-off valve that can allow coolant to drip on other parts of the vehicle. This can cause "Engine Maintenance Required" to be displayed on the instrument cluster or cause the A/C not to function normally. Although the flow shut-off valve is covered by Toyota’s New Vehicle Limited Warranty for 36 months or 36,000 miles (whichever comes first), we at Toyota care about the customers’ ownership experience. Toyota is providing coverage for repairs related to Flow Shut-off Valve Coolant Leak.
NHTSA #11022949 - ELECTRICAL SYSTEM Jun 24, 2025
Some 2021 – 2022 model year Avalon, 2018 – 2024 Camry, 2019 – 2025 model year Corolla, 2022 – 2025 model year Corolla Cross, and 2019 – 2025 model year RAV4 vehicles with A25A-FKS and M20A-FKS engines may have a MIL ON condition with one or more of the following Diagnostic Trouble Codes (DTCs) upon cold soak start up with engine coolant temperatures between 14°F – 41°F: •P030027 – Random/Multiple Cylinder Misfire Detected (Emission) Signal Rate of Change Above Threshold •P030000 – Random/Multiple Cylinder Misfire Detected •P030100 – Cylinder 1 Misfire Detected •P030200 – Cylinder 2 Misfire Detected •P030300 – Cylinder 3 Misfire Detected •P030400 – Cylinder 4 Misfire Detected
NHTSA #11020670
+14 more TSBs available in MECH AI's TSB explorer for this vehicle.
Common fixes
- Replace the cylinder 1 ignition coil
- Replace all spark plugs (always replace as a complete set)
- Replace, clean, or service the cylinder 1 fuel injector
- Repair damaged harness wiring to cylinder 1
- Head work or engine rebuild for compression-related root causes
About the 2020-2024 Toyota Camry
The 2020-2024 Toyota Camry was commonly sold with the following powertrains: 2.5L I4, 3.5L V6, 2.5L Hybrid I4. Common trims include LE, SE, XLE, XSE.
Why isolated-cylinder misfires are easier than P0300 alone
When the ECM can attribute the misfire to one specific cylinder, the diagnostic path is short: there are only a handful of parts unique to that cylinder. The swap test (move the coil to a different cylinder, see if the misfire follows) typically resolves a P0301 within 15 minutes of hands-on work.
When P0301 follows a coil but the coil tests good
Aftermarket coils — especially the discount bulk packs sold online — can test fine on the bench but fail under cylinder-pressure load. If a brand-new coil sets P0301 within days, replace it with an OEM or premium-aftermarket part. This is especially common on Ford modular engines and GM L83/L86 truck V8s.
P0301 on a direct-injection engine
On direct-injection engines (most modern Hondas, Mazdas, Hyundais, and many Fords from 2012 onward), carbon buildup on intake valves can cause single-cylinder misfires that ignition and fuel work will not fix. A borescope inspection through the intake port reveals the carbon. Walnut-shell blasting restores normal operation.