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Chris(aka-Moose)
Chris(aka-Moose), Nissan Technician
Category: Nissan
Satisfied Customers: 562
Experience:  16 years of experience
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1999 Nissan Frontier XE PO443 still after replacing purge

Customer Question

1999 Nissan Frontier XE PO443 still after replacing purge valve and checked connections.
JA: How many miles are on the car? Have you noticed any leaks lately?
Customer: 244,000 ish
JA: Are you fixing your Frontier yourself? What have you tried so far?
Customer: yes
JA: Anything else you want the mechanic to know before I connect you?
Customer: it runs fine just can pass smog
Submitted: 12 days ago.
Category: Nissan
Expert:  david craig replied 12 days ago.

Hi Im David, since you've checked the make sure the valve is getting power to it, or have a smoke test done to find the leak.connections and replaced the purge valve, you can do 2 things. do a continuity check of the wiring.

Customer: replied 12 days ago.
I thought PO443 error is strictly electrical related. I have not check the hoses. I do get the proper voltages as per the service manual. If I clear the error it returns quite promptly.
Expert:  david craig replied 12 days ago.

Possible causes - EVAP control system pressure sensor - Damage harness or connectors to the Purge Control Valve - The valve circuit is open or shorted - EVAP canister purge volume control solenoid valve may be faulty (The valve is stuck open)

Expert:  david craig replied 12 days ago.

This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass passage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the Engine Control Module (ECM). The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor from the EVAP canister is regulated as the air flow changes. The EVAP canister purge volume control solenoid valve uses a ON/OFF duty to control the flow rate of fuel vapor from the EVAP canister. The EVAP canister purge volume control solenoid valve is moved by ON/OFF pulses from the ECM. The longer the ON pulse, the greater the amount of fuel vapor that will flow through the valve.

If you have a leak the valve will fault.

Expert:  david craig replied 12 days ago.

do you need further assistance?