Evap System Frustration
05-29-2017, 10:08 AM
#11
Platinum Member
Join Date: 12-06-2009
Location: Alabama
Posts: 11,108
Don. You stated that Mitchell does not list P0455 but the OP, GIJOE1980 said his code was P0445
Not sure if the OP misprinted or his reader was in error.
Anyhow. Pulled this short list from one of ChevyMgr's old threads.(no P0445 here)
P0420 Catalyst System Low Efficiency
P0442 Evaporative Emissions (EVAP) System Small Leak Detected
P0443 Evaporative Emission (EVAP) Purge Solenoid Control Circuit
P0446 Evaporative Emissions (EVAP) Vent System Performance
P0449 Evaporative Emission (EVAP) Vent Solenoid Control Circuit
P0450 Fuel Tank Pressure (FTP) Sensor Circuit
P0451 Fuel Tank Pressure (FTP) Sensor Performance
P0452 Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage
P0453 Fuel Tank Pressure (FTP) Sensor Circuit High Voltage
P0454 Fuel Tank Pressure (FTP) Sensor Circuit Intermittent
P0455 Evaporative Emission (EVAP) System Large Leak
P0458 Evaporative Emission (EVAP) Purge Solenoid Control Circuit Low Voltage
P0459 Evaporative Emission (EVAP) Purge Solenoid Control Circuit High Voltage
Not sure if the OP misprinted or his reader was in error.
Anyhow. Pulled this short list from one of ChevyMgr's old threads.(no P0445 here)
P0420 Catalyst System Low Efficiency
P0442 Evaporative Emissions (EVAP) System Small Leak Detected
P0443 Evaporative Emission (EVAP) Purge Solenoid Control Circuit
P0446 Evaporative Emissions (EVAP) Vent System Performance
P0449 Evaporative Emission (EVAP) Vent Solenoid Control Circuit
P0450 Fuel Tank Pressure (FTP) Sensor Circuit
P0451 Fuel Tank Pressure (FTP) Sensor Performance
P0452 Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage
P0453 Fuel Tank Pressure (FTP) Sensor Circuit High Voltage
P0454 Fuel Tank Pressure (FTP) Sensor Circuit Intermittent
P0455 Evaporative Emission (EVAP) System Large Leak
P0458 Evaporative Emission (EVAP) Purge Solenoid Control Circuit Low Voltage
P0459 Evaporative Emission (EVAP) Purge Solenoid Control Circuit High Voltage
05-29-2017, 08:21 PM
#13
Thread Starter
Join Date: 05-23-2017
Location: dallas
Posts: 5
This is odd; Mitchell does not list P0445. But the web shows this:
https://www.obd-codes.com/p0445
If it is really P0443 it is the purge valve (under the hood)
The PCM/ECM monitors the voltage to the purge control valve and has detected a lower voltage than expected. It is a PWM circuit, not on/off.
Sometimes the ABS light will illuminate because the T/C is turned off.
Here is the VOM testing data for both valves:
Attachment 21751
https://www.obd-codes.com/p0445
If it is really P0443 it is the purge valve (under the hood)
The PCM/ECM monitors the voltage to the purge control valve and has detected a lower voltage than expected. It is a PWM circuit, not on/off.
Sometimes the ABS light will illuminate because the T/C is turned off.
Here is the VOM testing data for both valves:
Attachment 21751
05-29-2017, 09:59 PM
#14
Moderator
Join Date: 01-23-2009
Location: Fredericksburg,VA
Posts: 24,728
P0455 is large EVAP leak. Frequently a bad gas cap, or the O-ring between the valve and the charcoal canister is bad or the valve is stuck open.
https://www.obd-codes.com/p0455
https://www.obd-codes.com/p0455
05-30-2017, 09:59 AM
#15
Senior Member
Join Date: 09-16-2013
Location: Tampa, Florida
Posts: 1,408
Luckily the EVAP system really doesn't effect performance of the power train, so you can safely chug along until you get it fixed. The only issue that leaving a check engine light on presents in this case is that you will not be notified if a new, potentially serious, problem pops up. I recommend fixing asap, but know that the code indicates an issue that you can "just live with."
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