Apex Automotive & Emissions
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OBD-II Diagnostic Trouble Code

P0496EVAP Emission System High Purge Flow

Moderate Severity

At a Glance

What It Means

The EVAP system is detecting purge flow when none is commanded.

System

Emissions — EVAP

Can I Drive?

With caution — have it diagnosed promptly.

Severity

Moderate

Symptoms

  • Check Engine Light illuminated
  • Rough idle, especially after refueling
  • Hard start when hot
  • Rich fuel condition at idle

Common Causes

01Purge valve stuck open
02Purge valve leaking internally
03Faulty EVAP pressure sensor giving false readings

How We Diagnose P0496

01

Scan & Verify

Confirm P0496 and check for related codes that may share a root cause.

02

Live Data Review

Pull real-time sensor data to isolate whether the fault is electrical, mechanical, or software-related.

03

Component Test

Perform targeted tests on the specific circuit or component flagged by the code.

04

Root Cause Repair

Repair or replace only what is confirmed faulty — no parts-swapping guesswork.

05

Verify & Clear

Clear the code, perform a drive cycle, and confirm the monitor passes before returning the vehicle.

Related Services

Frequently Asked

Will code P0496 clear itself?

OBD-II codes do not clear themselves. The underlying fault must be repaired and the monitor must pass during a drive cycle before the light extinguishes.

Can I pass an Arizona emissions test with P0496 active?

No. Any active check engine light is an automatic emissions test failure in Arizona. The code must be resolved and the relevant monitor must complete before testing.

How long does a diagnostic take?

Most diagnostic appointments at Apex take 45–90 minutes. Complex electrical faults may require additional time for circuit testing.