In this guide, we will go over the potential causes of the diagnostic trouble code P0458. This code is common and it will store itself in the vehicle's computer and cause a check engine light on the dash. You will need to diagnose and repair the problem present to get rid of the check engine light.
This applies to Mitsubishi Outlander model years: 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, and most all other models such as the Outlander Sport, Mirage, Lancer, Galant etc equipped with the four-cylinder engine.
What does code P0458 mean?
This code is an emissions system code. Part of the evaporative control system has malfunctioned, and it is operating outside of what is considered normal.
If an EVAP systems check fails, a fluctuation in voltage happens that the vehicle's computer no longer considers normal, thus setting off a hard stored code on the computer.
- Loose gas cap
- Overfilling the gas tank
- Faulty purge control valve
- Broken, clogged, or faulty EVAP charcoal canister
- Faulty vacuum hoses
- Faulty fuel vapor hoses
- Faulty pressure/flow sensor
- Open or shorted EVAP purge control solenoid harness
- Faulty, corroded, loose, open, or shorted electrical components in the EVAP emissions system purge control valve circuit, including wiring or connectors
How do you diagnose trouble code P0458?
Start by pulling the codes from the vehicle with an OBDII scan tool, if there are other codes along with the P0458, that is an indicator of where to start looking for components in the EVAP system that are malfunctioning.
Always check the fuel cap to make sure it is closed properly, leaving the gas cap off is the most common cause of this code.
The second most common cause of this code is overfilling the gas. If you are someone who keeps pumping gas even after the pump has stopped on its own to get that extra little bit of gas or reach an even number on the dollar mark, then you are overfilling the gas tank. Overfilling the gas tank will flood the charcoal canister and cause it to become clogged, this will set off this code and the charcoal canister will need to be replaced.
Diagnosing this code further will require technical automotive knowledge including knowing how to work on electrical systems.
A professional OBDII scan tool will be required that can read system voltages, and technical charts with the correct voltages from the manufacturer will also be needed. At this point, it is advised to take the vehicle to the shop to have it diagnosed by a trained technician with the proper equipment.