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What P0303 means for your Toyota Tacoma
Your Tacoma dropped cyl 3. On the 2GR-FKS V6, cyl 3 is bank 1 passenger side. The 2GR-FKS has a well-documented coil-set aging pattern - if one coil fails past 100k miles, the others follow within 20k. P0303 + P0301 together is the dead giveaway you need a full coil set.
Top Causes of P0303 on the Toyota Tacoma
55%
#1 CAUSE
Coil Pack Set Aging (2GR-FKS V6)
The 2GR-FKS V6 ages its coil set together. P0303 plus P0301 or P0305 = full coil set needed. By 130k miles most 2GR engines have replaced at least one coil. Best practice: do all 6 at once with Denso 90919-02256 or NGK U5099. Cyl 3 sits front-bank passenger, easy access.
OEM Coil (1)
$80-$130
Set of 6
$320-$580
w/Labor
$110-$200/$420-$780
25%
#2 CAUSE
Worn Iridium Plug Set
Denso FK20HR11 iridium plugs at 120k miles. V6 has 6 plugs - rear-bank ones require intake removal. ALWAYS replace all 6 at once. Gap 0.043".
Plugs (6)
$48-$90
w/Labor
$280-$520
DIY
2 hrs
15%
#3 CAUSE
Fuel Injector Drift (2GR-FKS)
The 2GR-FKS uses port injection (still!) and the injectors can drift in flow rate over 100k miles, creating uneven fueling. Cyl 3 commonly drifts lean. A flow-bench cleaning of all 6 injectors usually solves it. Some shops use ultrasonic injector cleaning for under $200.
Injector Clean (6)
$180-$280
Set of 6 (new)
$420-$680
w/Labor
$280-$500
Most Affected Tacoma Model Years
| Year | Engine | Primary Cause | Typical Mileage | Notes |
|---|---|---|---|---|
| 2005-2015 | 4.0L 1GR-FE V6 | Coil pack #3 | 100k-180k | Slower aging than 2GR |
| 2016-2023 | 3.5L 2GR-FKS V6 | Coil set aging | 110k-170k | P0303 + P0301 = full set |
| 2024+ | 2.4L T24A-FTS Turbo | Carbon / coil | 30k-80k | New GDI turbo |
| 2005-2024 | 2.7L 2TR-FE 4-cyl | Coil pack #3 | 120k-200k | Bulletproof 4-cyl |
TSB info: Toyota TSB T-SB-0050-15 (coil replacement procedures); 2GR-FKS coil-set aging is a known pattern documented across many Tacoma forums and TSBs.
How to Diagnose P0303 on a Toyota Tacoma
- Scan for ALL misfire codes. P0303 alone = single coil. P0303 + P0301 or P0305 = full coil set needed.
- Swap coil 3 with coil 5. If P0303 becomes P0305, replace coil 3. On a 2GR past 110k miles, plan to replace the full set within 6 months.
- If full set is over 100k miles, replace all 6 plugs at the same time as coils - the rear-bank intake removal labor is the same.
Want a step-by-step walkthrough specific to your Toyota Tacoma? Run a $5.99 AI diagnosis report - we narrow the cause to your year, engine, and symptoms.
P0303 Toyota Tacoma FAQs
Why do 2GR-FKS coils all fail together?
Same manufacturing batch, same heat exposure, same age. The OEM coil insulation degrades from heat - once one coil fails, the others are within 10-30k miles. Replace the set for long-term reliability.
How much for a full coil set on a Tacoma?
$420-$780 with labor at a Toyota dealer, $320-$580 in parts if you DIY. Front-bank coils (1, 3, 5) take 30 minutes; rear-bank (2, 4, 6) need intake removal - add 90 minutes.
Will P0303 damage my Tacoma's engine?
Not if you fix it quickly. Flashing CEL = stop driving (catalyst damage risk - $1,200-$2,000 to replace). Steady CEL means you can drive to a shop. Don't ignore it for a long road trip.
Should I add a catch can to my 2GR-FKS?
Port injection means the 2GR doesn't suffer from GDI intake-valve carbon. A catch can is less critical here than on a GDI engine. Skip it unless you're running performance mods.