P0300 on a Toyota Camry
P0300 means random/Multiple Cylinder Misfire Detected. On the Camry, a few causes come up far more than others.
What P0300 usually means on a Camry
P0300 on a Camry is a random or multiple-cylinder misfire — the ECU sees the crankshaft speeding and slowing but can't pin the miss to one cylinder. On the 2AZ-FE it frequently traces back to that engine's well-known oil consumption fouling the spark plugs. Across generations, aging Denso coil-on-plug units and overdue plugs are the usual suspects. You'll typically feel a rough idle and a stumble under load, with a flashing light if the misfire gets bad enough to threaten the cat.
Most common causes on the Camry
- Worn spark plugs
Toyota's long-life iridium plugs often get skipped past 120k; a fresh set is the cheapest first move on any Camry.
- Aging ignition coils
Denso coil-on-plug units weaken with heat cycles, and a marginal coil can cause intermittent multi-cylinder misfires.
- 2AZ-FE oil consumption
The 2007-2009 four burns oil that fouls plugs — a classic root cause of P0300 on that engine.
- Vacuum or intake leak
A cracked PCV hose or leaking intake gasket leans out all cylinders and reads as a random misfire.
- Weak fuel delivery
A tired fuel pump or dirty injectors can starve several cylinders under load.
What P0300 costs to fix on a Camry
Plugs and coils make up the bulk of Camry misfire repairs; a full plug set is inexpensive and coils are moderate each. Four-cylinder access is easy, but the 2GR-FE V6's rear bank sits under the intake and adds labor. If the 2AZ-FE is burning oil, budget for the underlying consumption fix or the new plugs will foul again.
Fixing it
On a high-mileage four-cylinder, start with a fresh set of iridium plugs and read them as you pull them — oil-fouled plugs point at the 2AZ-FE consumption issue, while plain wear points at simple neglect. Swap a suspect coil to a different cylinder to see whether the misfire follows it.
For the full step-by-step diagnosis order (any vehicle), see the main P0300 guide.
Year, engine and mileage change the answer. Start a case and Redline weighs these causes against what your car shows, then names the check that would settle it.
Other codes on the Toyota Camry
Related symptoms
Toyota Camry problems & recalls by year
Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0300 behavior is covered on the main P0300 page. Confirm with a scan tool before buying parts.
P0300 on your Camry?
Every problem becomes a Case. Tell Redline what your Camry is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.