OBD Codes

P0458

Evaporative Emission Control System Purge Control Valve Circuit Low

Moderateevaporative

About P0458

The P0458 code indicates the PCM has detected a evaporative emission control system purge control valve circuit low condition in the evaporative emission control (EVAP) system. The EVAP system prevents fuel vapors from escaping into the atmosphere by routing them to the engine for combustion. A fault in this system can result in harmful fuel vapor emissions and a failed emissions test. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Check Engine Light (MIL) illuminated. Failed emissions test. Slight decrease in fuel economy. Gas cap warning light. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Damaged charcoal canister. Loose, damaged, or missing gas cap. Wiring issues in EVAP circuit. Faulty EVAP pressure sensor. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Connect an OBD-II scanner and read all stored trouble codes and freeze frame data. Inspect and tighten the gas cap; replace if damaged or worn. Perform a smoke test on the EVAP system to locate leaks. Inspect all EVAP hoses and connections for cracks or disconnections. Test the purge valve and vent valve with a multimeter and vacuum pump. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Powertrain (P) collection on OBD Codes. We provide comprehensive, up-to-date information to help you find solutions quickly.

Quick Answer

Can a loose gas cap cause an EVAP code?

Yes, a loose, damaged, or missing gas cap is one of the most common causes of EVAP system codes. Always try tightening the gas cap first and driving for a few days to see if the code clears.

Overview

The P0458 code indicates the PCM has detected a evaporative emission control system purge control valve circuit low condition in the evaporative emission control (EVAP) system. The EVAP system prevents fuel vapors from escaping into the atmosphere by routing them to the engine for combustion. A fault in this system can result in harmful fuel vapor emissions and a failed emissions test.

Symptoms

  • Check Engine Light (MIL) illuminated
  • Failed emissions test
  • Slight decrease in fuel economy
  • Gas cap warning light

Common Causes

  • Damaged charcoal canister
  • Loose, damaged, or missing gas cap
  • Wiring issues in EVAP circuit
  • Faulty EVAP pressure sensor

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
  2. 2Inspect and tighten the gas cap; replace if damaged or worn
  3. 3Perform a smoke test on the EVAP system to locate leaks
  4. 4Inspect all EVAP hoses and connections for cracks or disconnections
  5. 5Test the purge valve and vent valve with a multimeter and vacuum pump

Estimated Repair Cost

$50$600

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

Toyota CamryKia SoulHyundai SonataToyota Corolla

Related Codes

More Evaporative Codes

Frequently Asked Questions

Yes, a loose, damaged, or missing gas cap is one of the most common causes of EVAP system codes. Always try tightening the gas cap first and driving for a few days to see if the code clears.