An OBDII P0496 error code is a common issue if there is a problem with the evaporative emission control. Although this fault code doesn’t generally result in many fault codes, it’s best to treat the issue as soon as possible. Otherwise, you could be dealing with bigger and more costly expenses. We’ll tell you how to diagnose P0496 trouble codes and repair any problems.
What Does Code P0496 – EVAP Flow During a Non-Purge Condition Mean?
Code P0496 – EVAP (evaporative emission control) Flow During a Non-Purge Condition is a generic powertrain code and suggests that there was unwanted intake vacuum flow. This means the EVAP system was purging flow vapors when your vehicle should not have.
This system is responsible for keeping harmful fuel vapors from being released into the atmosphere. The EVAP system must run properly to prevent excess pollution from being released by your car.
The EVAP/fuel pressure sensor measures the vacuum in the EVAP system. If the power-train control module (PCM) detects an irregularity (excess vacuum or vacuum at an unexpected time), then your vehicle may display this code.
How Serious Is Code P0496?
Stop Driving
- If your vehicle is experiencing decreased performance, such as low gas mileage and slow acceleration
- There is a strong gasoline smell
Generally, you won’t experience any noticeable changes in your vehicle’s drivability. Still, you should still resolve P0496 issues quickly to prevent damage to your catalytic converter, which could cost you much more.
- EVAP/fuel pressure sensor
Symptoms
- Difficulty starting vehicle
- Engine is running rich
- Check engine light is illuminated
Causes
Since there are several possible causes for a P0496 error code, it’s important to diagnose it correctly. This fault code can be easily resolved by addressing less serious, and generally more inexpensive, issues, resulting from leaks from the EVAP system.
- Faulty/missing fuel cap
- Faulty purge or vent solenoid/valve
- Plugged EVAP canister
Some issues are more serious and will require more immediate attention. If your vehicle is not suffering from one of the above causes, it’s likely to be one of these.
- Faulty EVAP/fuel pressure sensor
- Leaking EVAP system hose
Solutions
A few different issues could be the cause of your P0496 error code. One of the most common issues lies with the EVAP canister purge solenoid valve. But, sometimes, it could be as simple as forgetting to put on the fuel cap.
1. Inspect your car’s fuel cap. Make sure it is tightly placed and in good condition. If it’s missing or damaged, you may need to buy a replacement.
2. With the engine off, remove the vacuum hose at the purge solenoid valve that goes back to the charcoal canister. Unplug the electrical connector at the valve. Start the engine, and check for a vacuum from the valve, where the hose was removed. You can use your finger or a vacuum gauge if you own one.
3. If the previous step indicated that there was a vacuum, then you will need to replace the purge solenoid valve. If there was no vacuum, then the problem with the valve could be intermittent or there is a problem with the EVAP system.
If the issue persists, your vehicle’s EVAP system likely has an air leak. Finding and repairing possible leaks are one of the easiest parts to fix, especially considering it may just be the result of a misplaced part.
4. Perform a visual inspection of the EVAP system to check for any leaks. Readjust and replace hoses/seals as necessary. You can use an EVAP smoke machine leak checker to help test for leaks. (See code P0455)
5. Check the EVAP canister and ensure there are no restrictions or blockages. Clean and replace if necessary.
You are likely dealing with a sensor issue if the above steps have not resolved the error code.
6. Remove the EVAP fuel pressure sensor (refer to your service manual to locate it). Use a multimeter, if available, to test the sensor. If the readings do not meet the expected values, then replace the sensor.
Code P0496 does not usually hinder your vehicle’s drivability but, sometimes, it can cause serious damage to the EVAP system. If you do not own some of the equipment required for a proper diagnosis, visit a mechanic to check any parts.
