Your Toyota’s check engine light is flashing, your car is shaking, and your OBD scanner just threw a Toyota P0302 code. That’s a cylinder 2 misfire — and yes, it needs attention. This guide breaks down exactly what’s causing it, where cylinder 2 actually lives in your engine, and how to fix it without throwing money at random parts.
What Is the Toyota P0302 Code?
Toyota P0302 means your engine’s computer — called the PCM or ECM — detected a misfire in cylinder 2. That means cylinder 2 isn’t burning its fuel-air mixture properly. It might be misfiring occasionally, or not firing at all.
The PCM doesn’t actually see inside the cylinder. Instead, it watches the crankshaft. Every time a cylinder fires, the crankshaft gets a tiny speed boost. If cylinder 2 doesn’t fire, the crankshaft slows down slightly during that window. The PCM catches this through the Crankshaft Position Sensor (CKP) and logs the fault.
Toyota uses two monitoring windows to judge how serious the misfire is:
| Monitoring Window | Misfire Threshold | MIL Behavior | Severity |
|---|---|---|---|
| 200-revolution window | >10% misfire rate | Flashing MIL | Critical — catalyst damage risk |
| 1,000-revolution window | >2% misfire rate | Steady MIL | Moderate — emissions fault |
A flashing check engine light is your car telling you to pull over. A steady light means fix it soon, but you’re not in immediate danger.
Where Is Cylinder 2 on a Toyota?
This trips up a lot of people. Cylinder 2’s location depends on what engine you have. Toyota always numbers cylinders starting from the front of the engine — the belt-and-pulley end, not the transmission end.
Inline 4-Cylinder (Camry, Corolla, RAV4, Prius)
On a Toyota inline-4 like the 2AZ-FE or 2ZR-FE, cylinders run 1 through 4 from front to back. Most of these engines sit sideways in the engine bay (transverse mount). So:
- Cylinder 1 = passenger side
- Cylinder 2 = one over toward the driver’s side
- Firing order: 1-3-4-2
V6 Engines (Camry V6, Avalon, Highlander, Sienna, Tacoma, 4Runner)
For transverse V6s like the 1MZ-FE and 3MZ-FE, Bank 1 sits near the firewall and Bank 2 faces the radiator.
- Cylinder 2 = front bank (Bank 2), passenger side end
For longitudinal V6s like the 3.4L 5VZ-FE in the Tacoma and 4Runner, Bank 2 is the driver’s side bank, and cylinder 2 sits at the front.
V8 Engines (Tundra, Sequoia)
On the 4.7L 2UZ-FE, cylinder 2 sits at the front of the driver’s side bank. Firing order: 1-8-4-3-6-5-7-2.
| Engine Type | Cylinder 2 Location | Firing Order |
|---|---|---|
| Inline-4 (2.2L–2.5L) | 2nd from passenger side | 1-3-4-2 |
| V6 Transverse (3.0L–3.5L) | Front bank, passenger-side end | 1-2-3-4-5-6 |
| V6 Longitudinal (3.4L–4.0L) | Driver-side bank, front | 1-2-3-4-5-6 |
| V8 (4.7L) | Driver-side bank, front | 1-8-4-3-6-5-7-2 |
What Causes Toyota P0302?
Every misfire comes down to three things: spark, fuel, or compression. If any one of them fails in cylinder 2, you get a P0302. Here’s what to look for.
Ignition System Problems
Bad ignition coils and worn spark plugs are the most common cause on Toyotas — especially models with coil-on-plug (COP) setups, which is nearly everything built after 2000.
Ignition coil failure signs:
- Misfire gets worse under load (hill climbing, towing)
- The coil’s rubber boot has cracks or black carbon tracking
- Internal windings have broken down from heat over time
Spark plug failure signs:
- Electrode is worn or the gap is too wide
- Plug is fouled with carbon (rich running) or oil (valve seal leak)
- Plug hasn’t been changed in 60,000–100,000+ miles
Toyota recommends Iridium or Platinum plugs, and both Denso and NGK are factory-approved. Denso’s U-Groove design works well for everyday driving and hybrids. NGK tends to hold up better in high-load situations like towing.
Quick tip: If your last spark plug change was over 60,000 miles ago on a direct-injection engine (like the 2GR-FKS), that’s likely your culprit right there.
Fuel System Problems
A clogged or faulty injector on cylinder 2 is the next suspect. Two failure modes exist:
- Stuck closed / restricted: Cylinder runs lean (too much air, not enough fuel). Hard to ignite.
- Stuck open / leaking: Cylinder runs rich. Raw fuel smell from the exhaust. Plug gets soaked and won’t fire.
If the PCM also logs a P0202 (Injector Circuit Malfunction) alongside your P0302, the injector’s electrical circuit is the problem, not just the spray pattern.
Vacuum Leaks
An air leak near the cylinder 2 intake runner tricks the PCM. Extra air sneaks in after the MAF sensor, so the fuel mixture goes lean without the computer knowing. Vacuum leaks are loudest at idle, when intake vacuum is highest.
A large vacuum leak usually causes a P0300 (random misfire). A localized leak right at cylinder 2’s intake port tends to isolate the fault to P0302.
Low Compression
This is the most expensive scenario. If cylinder 2 can’t hold compression, the air-fuel mix won’t ignite efficiently regardless of how good the spark and fuel are.
Common mechanical causes:
- Failed head gasket — common on the 2.4L 2AZ-FE (Camry/RAV4 2002–2009) and 1.8L 2ZR-FXE (Prius)
- Burnt or sticking valve — from carbon buildup or incorrect valve lash
- Worn piston rings — especially on high-mileage engines without regular oil changes
Why Are Your VSC, TRAC, and 4WD Lights On Too?
If you’ve got P0302 plus a cluster of warning lights — VSC, TRAC, and 4WD — don’t panic. That’s not multiple failures. That’s Toyota’s system working as designed.
Here’s why it happens: VSC and TRAC systems rely on the engine to adjust torque instantly during stability events. If the engine’s misfiring, the PCM can’t guarantee accurate torque response. So it proactively disables those systems to prevent dangerous handling interventions. Fix the misfire, clear the codes, and those lights go off on their own.
How to Diagnose Toyota P0302 Step by Step
Don’t just start replacing parts. Follow this sequence and you’ll find the actual problem.
Step 1: Scan for All Codes
Pull all codes, not just P0302. Multiple misfire codes (P0300, P0301, P0303) point toward a bigger issue — fuel pump failure, vacuum leak, or a timing problem. Check the Freeze Frame data too. Misfire at high RPM under load? Focus on the coil and fuel system. Misfire at idle? Think vacuum leak or mechanical issue.
Step 2: Swap the Ignition Coil
This is the fastest and cheapest test. Swap the coil from cylinder 2 with cylinder 1, clear the codes, and drive it. If the code becomes P0301, the coil is bad — replace it. If it stays P0302, swap the spark plug next using the same method. Still P0302 after both swaps? The ignition system is fine. Move on.
Step 3: Test the Fuel Injector
Use a digital multimeter to check injector resistance — expect 10 to 16 ohms on most Toyota injectors. Use a noid light to confirm the PCM is sending a firing signal. If the circuit checks out but you suspect restricted flow, try swapping the injector to another cylinder and see if the misfire follows.
Step 4: Compression Test
If ignition and fuel check out, pull the plugs and test compression. A healthy Toyota should show 150–200 psi with no more than 10–15% variation between cylinders. Low compression in cylinder 2? Follow up with a leak-down test:
- Air escaping into intake → leaking intake valve
- Air escaping into exhaust → leaking exhaust valve
- Bubbles in radiator → failed head gasket
- Air from oil filler cap → worn piston rings
Model-Specific Issues You Should Know About
Prius (2010–2015) — 1.8L 2ZR-FXE
The 3rd-gen Prius is notorious for misfire codes, often with a cold-start rattle. Carbon and oil soot build up in the EGR system and intake passages. The clog can hit cylinder 2’s air port harder than others, especially after a cold soak overnight. Toyota released an updated intake manifold and EGR valve for this exact problem.
Camry / RAV4 (2002–2009) — 2.4L 2AZ-FE
This engine has a known weakness: head bolt threads pull out of the block, usually near cylinders 2 and 3. When the clamping force drops, the head gasket fails. If your P0302 comes with slow coolant loss and no external leak, check this before replacing anything else.
Older V6 Models (1MZ-FE / 3MZ-FE) — Avalon, Camry V6
Toyota issued TSBs EG008-04 and EG005-04 for coil failures on these engines. If you own a late-90s to mid-2000s V6 Toyota and you’re chasing P0302, the fix is often replacing the whole set of coils — not just cylinder 2’s — because they came from a defective manufacturing batch.
What Does Fixing Toyota P0302 Cost?
Your repair cost depends heavily on which engine you have and what’s actually broken. Inline-4 engines are the cheapest to service because everything sits right on top. V6 engines often require removing the intake plenum to reach the rear plugs and coils, which drives up labor significantly.
| Repair | Parts Cost | Labor Notes |
|---|---|---|
| Diagnostic scan | $0 (DIY) / $50–$150 (shop) | Required first step |
| Single ignition coil | $50–$150 | 0.5–1.5 hrs labor |
| Full spark plug set | $40–$100 | 0.5 hrs (I4) / 3+ hrs (V6) |
| Fuel injector | $100–$300 | Labor-intensive |
| Head gasket repair | $1,500–$2,500+ | Extensive teardown required |
One real-world example: a 2003 Camry V6 spark plug and coil job ran $1,500 at a shop — 8 hours of labor because of how buried the rear cylinder coils are.
How to Prevent P0302 From Coming Back
Staying ahead of this code is straightforward:
- Stick to your spark plug intervals. Port-injection engines (FE series) need plugs every 100,000–120,000 miles. Direct-injection engines (FKS series) need them at 60,000 miles.
- Use OEM-quality parts. Denso and NGK are your two options. Cheap off-brand coils and plugs create more problems than they solve.
- Keep your intake clean. If you own a Prius or any GDI Toyota, an intake cleaning at 60k miles prevents carbon buildup from triggering future misfires.
- Don’t ignore a steady check engine light. A small misfire becomes a dead catalytic converter if you ignore it long enough — and that’s a $1,000+ mistake.
Toyota P0302 is rarely a death sentence for your engine. Follow the diagnostic steps, don’t skip the swap test, and you’ll find the real culprit without burning cash on guesswork.
