The P1448 code is a Nissan/Infiniti-specific trouble code that means the EVAP canister vent control valve is stuck open (or electrically failed in the open position). This is essentially the opposite of the more common P1446 (stuck closed).
When the valve cannot close, the ECM cannot build pressure/vacuum for the EVAP leak test → check engine light + failed emissions.
What Exactly Does P1448 Mean?
During the EVAP monitor, the ECM commands the vent valve closed. If it still sees atmospheric pressure (no change), it assumes the valve is stuck open and sets P1448.
Long-tail keywords: P1448 Nissan vent valve stuck open fix, Infiniti G35 G37 QX56 P1448 EVAP vent control valve replacement.
Common Symptoms of P1448
- Check Engine Light illuminated
- Failed emissions / smog test
- Occasional fuel odor (rare)
- Difficulty refueling in some cases
- No drivability problems
Most Common Causes
- Faulty vent control valve (same part as P1446 – Nissan 14935-AM60A/AM60B/JF00B)
- Broken or stuck plunger inside the valve
- Water intrusion or corrosion causing the solenoid to stay energized/open
- Wiring short to power keeping the valve open
- Clogged vent filter/screen (rare)
Step-by-Step Diagnosis
- Scan with a scanner that can actuate the vent valve
- Command valve closed → should hear a click and airflow should stop
- Apply 12V directly → valve should close (no airflow from vent port)
- Check wiring and connector for damage or shorts
- Inspect vent hose and filter for blockage
Best Diagnostic Tool for P1448 in 2025: iCarsoft CR Ultra P
Generic OBD2 tools cannot command the vent valve on Nissan/Infiniti. The iCarsoft CR Ultra P gives you full bi-directional control and live data:
- Actuate vent valve open/closed in real time
- Run complete EVAP system tests
- Perfect coverage for Altima, Maxima, Pathfinder, Frontier, Rogue, Sentra, Titan, Armada, G35/G37, Q50/Q60, QX56/QX80 and all 1996–2025+ models
- Topology mapping + 41+ service functions
Get iCarsoft CR Ultra P – Fix P1448 in Minutes
Typical Repair Costs
| Repair | Average Cost (Parts + Labor) |
|---|---|
| Replace vent control valve only | $130–$320 |
| Valve + wiring repair | $250–$550 |
| Full canister + valve replacement | $600–$1100 |
Frequently Asked Questions (FAQ) – P1448
Can I drive with P1448?
Yes – no performance or safety issue, but you will fail emissions testing.
Most common vehicles that throw P1448?
Nissan Pathfinder, Frontier, Xterra, Altima (2000–2015); Infiniti QX56, FX35, G35 – especially in wet/salty regions where the valve corrodes.
Is P1448 the same part as P1446?
Yes – same vent control valve. Stuck closed = P1446, stuck open = P1448.
Best scanner for Nissan EVAP vent valve testing?
iCarsoft CR Ultra P – full bi-directional control at a fraction of dealer tool cost.
External resource: OBD-Codes.com P1448
