Plain English
What P0455 means for your Nissan Altima
P0455 on the Altima is usually a worn gas cap or a stuck canister vent control valve at the rear. Nissan's vent control valves are exposed to road grit and can clog or stick open. The charcoal canister can also crack at high mileage. Half the time it's just the gas cap.
🎯 Top Causes on the Nissan Altima
45%
#1 CAUSE
Worn Gas Cap
Nissan gas caps wear at 80k-130k miles. Tighten to 3 clicks first. If code persists, replace with Nissan OEM cap.
Tighten
Free
OEM Cap
$15-$28
Aftermarket
$8-$15
30%
#2 CAUSE
Canister Vent Control Valve
Located at the charcoal canister, this valve is meant to seal during EVAP self-test. Dirt and road salt can lodge it open. Removable, cleanable with brake cleaner; replace if seal is damaged.
Cleaning
Free DIY
New Valve
$50-$90
w/Labor
$90-$200
15%
#3 CAUSE
Charcoal Canister
Plastic housing on the canister cracks at 100k+ miles, especially in cold-winter regions. Inspect under the rear of the vehicle for visible damage and fuel smell.
Canister
$80-$220
w/Labor
$160-$400
DIY Time
60-90 min
10%
#4 CAUSE
EVAP Hose / O-ring
Cracked rubber hose along the frame rail or a degraded O-ring at the canister. Smoke-test reveals leaks.
Hose / O-ring
$10-$30
Smoke Test
$80-$140
w/Labor
$60-$180
🚗 Most Affected Altima Model Years
| Year | Engine | Primary Cause | Typical Mileage | Notes |
|---|---|---|---|---|
| 2007-2012 | 2.5L QR25DE | Gas cap + vent valve | 80k-150k | Common high-mileage P0455 |
| 2013-2018 | 2.5L QR25DE | Gas cap | 60k-120k | Updated EVAP system |
| 2007-2018 | 3.5L VQ35DE | Gas cap + canister | 70k-140k | Same EVAP design |
🔧 How to Diagnose P0455 on a Nissan Altima
- Tighten gas cap to 3 clicks, drive 100 miles. Free, very common Altima fix.
- Inspect canister vent valve. Pull the valve, blow through it - should be open with vacuum, closed without. Clean with brake cleaner if dirty.
- Smoke-test if needed. $80-$140.
Want a step-by-step walkthrough specific to your Nissan Altima? Run a $5.99 AI diagnosis report - we narrow the cause to your year, engine, and symptoms.