P0300 on Toyota vehicles
Random or Multiple Cylinder Misfire — what it means on a Toyota, whether it's safe to drive, and the fixes by model and year.
P0300 on a Toyota means random or multiple cylinder misfire. Stop driving and diagnose it before continuing — it can signal an unsafe condition. The most common cause is worn or fouled spark plugs (all cylinders due for replacement) (typically $60–$350). Pick your Toyota model below for its known failure patterns, recalls, and TSBs.
What does P0300 mean on a Toyota?
P0300 is set when the engine control module's misfire monitor detects that combustion is failing in more than one cylinder, or that misfires are occurring randomly across cylinders rather than being isolated to a single one. The misfire monitor works by measuring tiny variations in crankshaft rotational speed — a missed combustion event causes the crankshaft to decelerate by a detectable amount. When the ECM cannot attribute the event to a single cylinder, it sets P0300.
P0300 is a standardized OBD-II code, so its definition is the same on every Toyota. What differs by model and engine is which cause is most likely — pick your Toyota model below for a diagnosis tuned to its known failure patterns, recalls, and TSBs.
Is it safe to drive a Toyota with P0300?
No. P0300 is a high-severity code — avoid driving your Toyota until it is diagnosed and repaired, as it can indicate an unsafe condition or risk further damage.
What causes P0300 on a Toyota?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Worn or fouled spark plugs (all cylinders due for replacement) — Especially common past 80,000 miles on platinum or iridium plugs. | Most common | $60–$350 |
| Failing ignition coils — coil-on-plug systems | Most common | $80–$600 |
| Vacuum leak causing lean misfire across all cylinders | Common | $80–$500 |
| Low fuel pressure (weak pump, clogged filter) | Common | $80–$900 |
| Clogged or leaking fuel injectors | Occasional | $150–$1,500 |
| Carbon-fouled intake valves (direct-injection engines) | Occasional | $400–$900 |
| Low engine compression (worn rings, burnt valve, head gasket) | Rare | $1,500–$5,000 |
| Failed crankshaft or camshaft position sensor causing timing issues | Rare | $150–$550 |
Repair costs are typical US ranges and vary by Toyota model, model year, and labor rate. A diagnostic trouble code is a symptom, not a guaranteed failed part — confirm the root cause before replacing anything.
P0300 by Toyota model
Select your Toyota model and year for a P0300 diagnosis tuned to that vehicle's failure patterns, recalls, and TSBs.
Toyota RAV4
691 NHTSA owner complaints · 9 recalls on record across the years covered below.
Toyota Camry
842 NHTSA owner complaints · 6 recalls on record across the years covered below.
Toyota Corolla
721 NHTSA owner complaints · 8 recalls on record across the years covered below.
Toyota Tacoma
583 NHTSA owner complaints · 15 recalls on record across the years covered below.
Toyota 4Runner
170 NHTSA owner complaints · 16 recalls on record across the years covered below.
Toyota Highlander
650 NHTSA owner complaints · 11 recalls on record across the years covered below.
Toyota Sienna
393 NHTSA owner complaints · 22 recalls on record across the years covered below.
Complaint and recall counts are NHTSA totals for the model years covered on this site, not counts specific to P0300.
P0300 on other makes
Other codes on Toyota vehicles
P0300 on a Toyota: frequently asked questions
What does diagnostic trouble code P0300 mean on a Toyota?
P0300 is set when the engine control module's misfire monitor detects that combustion is failing in more than one cylinder, or that misfires are occurring randomly across cylinders rather than being isolated to a single one. The misfire monitor works by measuring tiny variations in crankshaft rotational speed — a missed combustion event causes the crankshaft to decelerate by a detectable amount. When the ECM cannot attribute the event to a single cylinder, it sets P0300. P0300 is a standardized OBD-II code, so the definition is the same on every Toyota — which cause is most likely varies by model and engine.
What are the symptoms of P0300 on a Toyota?
Check Engine Light flashing (severe misfire) or steady (minor misfire). Rough idle and noticeable engine shake at a stop. Hesitation or stumble under load. Loss of power, especially at higher RPM or on hills. Reduced fuel economy. Smell of raw fuel from the exhaust. Possible catalytic converter damage with prolonged operation
What causes P0300 on a Toyota?
Worn or fouled spark plugs (all cylinders due for replacement) (most-common). Failing ignition coils — coil-on-plug systems (most-common). Vacuum leak causing lean misfire across all cylinders (common). Low fuel pressure (weak pump, clogged filter) (common). Clogged or leaking fuel injectors (occasional). Carbon-fouled intake valves (direct-injection engines) (occasional). Low engine compression (worn rings, burnt valve, head gasket) (rare). Failed crankshaft or camshaft position sensor causing timing issues (rare)
Is it safe to drive a Toyota with P0300?
No. P0300 is a high-severity code — avoid driving your Toyota until it is diagnosed and repaired, as it can indicate an unsafe condition or risk further damage.