mjones123

I have a 2006 Honda Civic w/ 1.8L engine. The "check engine" light recently came on. I hooked-up an OBDII analyzer and found there was an active P2422 fault; the only active fault. I understand that this fault is for a stuck EVAP canister vent valve. I replaced the EVAP vent valve with part from Honda; and reset fault. Same fault came back after driving a few miles. What is most likely cause of P2422 fault when the vent valve is brand new?

DCFIVER

Why did you replace the valve? What testing was done to come to that conclusion? Did you read the code set criteria for this code?

mjones123

The OBDII analyzer that I used was borrowed from an Autozone store. The printout that I got from Autozone noted the fault code ID & description; and recommended to replace the vent valve. Vent valve wasn't very expensive and pretty easy to replace; so that's what i did. Seems you may know a better solution and procedure. What should I have done/do? Any help is appreciated.

DCFIVER

Shouldve have read the code set criteria and formulated a diagnostic path. Replacing a part based on a code alone is a fools errand.

Autozone is in the business of selling parts,not fixing cars.

Here is the criteria:

General Description: The fuel tank pressure (FTP) sensor output indicates about atmospheric pressure 0 kPa (0 in.Hg, 0 mmHg) before purge starts since the evaporative emission (EVAP) canister vent shut valve is normally open (open to the atmosphere). The sensor indicates a negative pressure value (vacuum) during purging. When the FTP sensor indicates vacuum after starting the engine, there is the possibility of an FTP sensor zero point shift failure or an EVAP canister vent shut valve stuck closed failure. So the engine control module (ECM)/powertrain control module (PCM) monitors the FTP sensor output after purge starts. The ECM/PCM detects a malfunction of the EVAP canister vent shut valve if the output indicates excessive vacuum. However, if the fuel tank internal pressure is below the specified value (excessive vacuum is detected) when starting the engine, the malfunction detection should be done as follows because it is difficult to distinguish the FTP sensor range problem (P1454) from the EVAP canister vent shut valve stuck closed (P2422).

1. If neither Temporary DTC (P1454 nor P2422) is stored, both DTCs are stored.

2. If both Temporary DTCs (P1454 and P2422) are stored and excessive vacuum is detected, both DTCs are stored.

3. If either Temporary DTC (P1454 or P2422) is stored and excessive vacuum is detected, the ECM/PCM stores the DTC of the Temporary DTC that was stored.




The above is an excerpt from Honda service information. I cannot simply tell you whats wrong because I dont know. You need to do some testing. Power,ground,PCM control and the fuel tank pressure sensor all should be checked.

You should at least have a service manual,yes?

tech8

There was a Honda technical service bulletin issued before, where spider webs may be clogging the EVAP canister vent tube.

See link: https://www.carmd.com/Tsb/Download/88213/A11-036

mjones123

DCFIVER & tech8. Thx for help

TomCat39

Also the general info lookup of P2422 has all of these possibilities for investigation:

What causes the P2422 code?

• Faulty vent valve
• Faulty vent valve control solenoid
• Faulty pressure sensor
• Faulty purge control solenoid
• Faulty flow sensor
• Loose or missing fuel cap
• Vacuum hoses that are damaged, loose or broken
• Fuel vapor hoses that are damaged, loose or broken
• EVAP wires that are damaged, broken or have shorts
• EVAP connectors that are damaged or corroded
• Faulty PCM

mjones123

I replaced the EVAP canister vent tube; and problem solved!
Fault hasn't returned after clearing the fault during repair.
New vent tube cost a whopping $16 from Honda.
End of old vent tube that connects to car body did get damaged during removal; so I recommend to replace vent tube rather than try to manually remove spider webs from inside of tube.
Thank you for your help.