P0300 on a Toyota
Quick answer
On some Toyota four-cylinder engines, including the documented 2AZ-FE used in many 2007 to 2009 Camry and RAV4 models, above-normal oil consumption is a known contributor to misfire codes as oil fouls spark plugs over time.
Severity 3 of 4. Short trips only.
Fix now · Short trips only
| Code | P0300 |
|---|---|
| Standard name | Random/Multiple Cylinder Misfire Detected |
| Make | Toyota |
| Severity | Fix now (3 of 4) |
| Safe to drive | Short trips only |
| Tool needed | Scanner with live data |
TOPDON TopScan Lite OBD2 Scanner, Bidirectional Scan Tool, 8 Resets & AI
Adds live sensor streams and freeze frame, which is what turns a code into a diagnosis rather than a guess.
Coverage varies by tool and by model year, so check a specific tool against a specific vehicle before buying.
What is different about P0300 on a Toyota?
The 2AZ-FE oil consumption issue is one of the more specifically documented Toyota misfire causes tied to a particular engine and model year range.
What Toyota owners run into with P0300
2AZ-FE oil consumption: The 2AZ-FE four-cylinder engine, used in many 2007 to 2009 Camry and RAV4 models, has a documented pattern of above-normal oil consumption. Oil reaching the combustion chamber and fouling spark plugs over time is a known contributor to misfire codes on this specific engine and generation.
Ignition coil aging as a more generic cause: On Toyota engines outside the documented 2AZ-FE oil consumption pattern, aging ignition coils remain a more generic and common cause of random misfire codes, similar to most other makes.
What to check first on a Toyota
The order below narrows the generic P0300 list down to what is worth checking first on this make. It is a starting order, not a diagnosis: patterns are generation specific and a vehicle outside those generations may have none of them.
Check in this order
- Check oil consumption history and inspect spark plugs for oil fouling if the engine is a documented 2AZ-FE from the affected years
- Inspect ignition coils for wear or failure
- Check spark plug condition and gap generally
- Check for vacuum leaks or fuel delivery issues if ignition components test normally
The generic picture behind P0300
The computer counts tiny fluctuations in crankshaft speed between each firing event and uses them to detect when a cylinder fails to fire cleanly. This code sets when those misfire events are spread across multiple cylinders rather than concentrated on one, which points to a cause that affects the whole engine instead of a single spark plug or injector. A random misfire is often a fuel, air or ignition supply problem shared by every cylinder.
Everything on the main P0300 page still applies here. This page narrows the cause list to the patterns documented on Toyota vehicles, it does not replace the underlying definition.
The generic version of this code
Tools that can diagnose P0300
Adds live sensor streams and freeze frame, which is what turns a code into a diagnosis rather than a guess.
- LJPXHHU
OBD2 Bluetooth Scanner Car Code Reader for iOS, Android and Windows
- wireless
$13.98 Check pricePrices change often - Veepeak
Veepeak Mini Bluetooth OBD2 Scanner Code Reader for Android (NOT for iOS)
- wireless
$14.99 Check pricePrices change often - MOCATEC
WiFi ELM327 OBD2 Adapter WiFi ELM 327 OBD Scanner for Universal 12V Vehicle
- wireless
$15.95 Check pricePrices change often - UMEIJA
OBD2 Scanner Diagnostic Tool, Car Scanner for iOS & Android, Bluetooth 5.4
- wireless
$29.99 Check pricePrices change often
Common questions
Which Toyota engine is documented for oil consumption causing misfires?
The 2AZ-FE four-cylinder engine, used in many 2007 to 2009 Camry and RAV4 models, has a documented pattern of above-normal oil consumption that can lead to oil-fouled spark plugs and resulting misfire codes on that specific engine and generation.
Does high oil consumption always cause a misfire code eventually?
Not necessarily every vehicle, but sustained oil consumption reaching the combustion chamber and fouling spark plugs over time is a documented contributor to misfire codes on the affected 2AZ-FE engines, making spark plug and oil consumption inspection worthwhile on these specific vehicles.