P0496 Chevy Chevy Silverado : Evaporative emission system high purge flow-diagnosis

The most frequent trouble code with the Chevy Silverado The Code P0496. The code refers to a number you receive when your Silverado is plugged into an OBDII scanner.

Similar: P0420 Chevy Silverado

Chevy Silverado P0496 Symptoms

A Chevy Silverado P0496 code is often accompanied with an intermittent idle. In order to determine the right idle speed, your engine may rev up or down. It will usually happen after you have purchased gas. Sometimes it might not even start at the station.

If you’re old enough to have driven a carbureted vehicle the old stomp the gas and crank the engine method does actually help start the car. It is because the mixture of air and fuel has been contaminated.

Chevy Silverado P0496 Meaning

The universal OBDII code P0496 can be used to diagnose trouble codes. The code can be used regardless of the make and model of your vehicle. Technically, the code stands for:

Evaporative Emissions System High Purge Flow

The EVAP captures any fuel vapor in the fuel tank. They are then sent to the intake to incite the regular combustion process.

The Chevy Silverado computer will emit the OBDII P0496 code if it detects the EVAP system purging in an unintentional manner.

Chevy Silverado P0496 Causes

The Chevrolet Silverado's P0496 code can be caused by many factors. The most frequent problems that cause this code are listed below.

Vapor Canister Purge Valve– The most common culprit with the P0496 trouble code and the Chevy Silverado is going to be the vapor canister purge valve. When it goes bad, it typically causes issues with the vehicle’s idle speed. It is particularly true after filling up your vehicle.

It’s really easy to replace. You will need to locate and delete a few clips. There is a  a great YouTube video on diagnosing the problem below.

PCM– It is possible that the engines computer system itself has gone bad and is registering a P0496 when it shouldn’t be. However, you shouldn't start there.

Connectivity– It is possible for shorts in the wiring harness leading to the Vapor Canister Purge Valve has gone bad. You can check it.

Fuel Cap– A bad fuel cap can cause the P0496 code to be thrown for sure. Often, you’ll get a message informing you that the fuel cap is off even when it is on. It may be worth your time to change the fuel cap on your Chevy Silverado to see if it disappears.

Oil Tank Pressure Sensor– If the fuel tank pressure sensor has gone bad, it can cause all sorts of problems, including the P0496 code.

Here’s a good video on it:

We wish you all the best in diagnosing your Suburban's problems. This should help.  You can add any additional information by leaving a comment.