Faulty EVAP purge solenoid (stuck open, stuck closed, or internally shorted).; Damaged, disconnected, or clogged EVAP purge hose between the intake manifold and the purge solenoid.; Leaking or disconnected EVAP canister purge line at the canister or intake.; Failed fuel tank pressure sensor sending inaccurate readings to the PCM.; Wiring issue in the purge solenoid circuit, such as an open, short, or corroded connector.; Sticking or failed EVAP canister purge valve due to carbon buildup.; PCM software glitch or internal fault (rare, but possible on older Mazdas).

DTC codes / Mazda codes / P1443

P1443 · MazdaEVAP System Purge Flow Fault

Q: What does code P1443 mean?

EVAP System Purge Flow Fault. P1443 on a Mazda means the powertrain control module (PCM) has detected a fault in the evaporative emission (EVAP) system's purge flow, where the computer expects a certain change in fuel tank pressure or purge flow when it commands the purge solenoid to open. The PCM monitors the purge solenoid circuit and the resulting pressure change, and when the response falls outside the expected range, it stores this code.

P1443 on a Mazda means the powertrain control module (PCM) has detected a fault in the evaporative emission (EVAP) system's purge flow, where the computer expects a certain change in fuel tank pressure or purge flow when it commands the purge solenoid to open. The PCM monitors the purge solenoid circuit and the resulting pressure change, and when the response falls outside the expected range, it stores this code.

SystemPowertrain

Code typeMazda specific

SeverityLow

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other symptoms.
A faint fuel odor around the vehicle, especially after refueling or when the engine is idling.
Rough idle or a slight stumble when the purge solenoid is commanded open.
Slightly reduced fuel economy if the purge system remains open or closed incorrectly.
In some cases, a noticeable hesitation during light acceleration.
No drivability symptoms at all besides the warning light.

Common causes, most likely first

Faulty EVAP purge solenoid (stuck open, stuck closed, or internally shorted).
Damaged, disconnected, or clogged EVAP purge hose between the intake manifold and the purge solenoid.
Leaking or disconnected EVAP canister purge line at the canister or intake.
Failed fuel tank pressure sensor sending inaccurate readings to the PCM.
Wiring issue in the purge solenoid circuit, such as an open, short, or corroded connector.
Sticking or failed EVAP canister purge valve due to carbon buildup.
PCM software glitch or internal fault (rare, but possible on older Mazdas).

How to diagnose and fix it

Connect a scan tool and verify P1443 is the only code; check freeze-frame data for engine conditions when the fault set.
Inspect all EVAP hoses and connections between the purge solenoid, intake manifold, and canister for cracks, disconnects, or clogs.
Test the purge solenoid with a scan tool by commanding it on and off while listening for a click; measure resistance if specified.
Check the fuel tank pressure sensor reading for plausibility with the key on, engine off, and compare to actual pressure if possible.
Perform a smoke test on the EVAP system to locate any leaks that could mimic a purge flow fault.
Inspect the purge solenoid wiring and connector for corrosion, tightness, and continuity to the PCM.
If all else checks out, reflash or replace the PCM only after confirming no other faults exist.

Before you replace the purge solenoid

A clogged or disconnected purge hose often sets P1443 without any visible leak, so always inspect the hose routing and condition before condemning the solenoid.
The fuel tank pressure sensor can drift and cause a false purge flow fault; compare its reading to a known-good sensor or use a scan tool to watch live data during a purge test.
On some Mazda models, a stuck-open purge solenoid can cause a rough idle that mimics a vacuum leak, leading to misdiagnosis of intake gaskets or PCV hoses.
P1443 can be set by a loose fuel cap if the EVAP system cannot hold pressure during the purge monitor, so always check the cap seal and tighten it properly.
After repairs, clear the code and perform a drive cycle that includes a cold start and steady cruise to allow the EVAP monitor to run and confirm the fix.

Can I keep driving with P1443?

You can generally continue driving with P1443 because it does not affect engine safety or performance significantly, but avoid topping off the fuel tank and have the system inspected soon to prevent a small EVAP leak from worsening.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Mazda vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.