P0446 and P0443 96 Maxima

[asand1]

I replaced my down stream O2 sensor this weekend and cleared the ECU after two years of not checking the codes. I just assumed the CEL was only for the O2.
Well the CEL popped up again with DTC 0903,0304, and 0807. I know 0304 (KS) is bogus, triggered by the other two.
Could 0903 and 0807 share a common problem triggering both?

DTC 0903=P0446=EVAP Canister Vent Control Valve Circuit

DTC 0807=P0443=EVAP Canister Purge Control Valve/Solenoid Valve

The valve on the canister has a rusty shaft inside. I tried removing it to clean and oil yesterday, but one of the thread inserts is spinning in the plastic canister.

I removed the whole canister today and tested the valve with a battery. It would carry current but would not actuate. I turned the canister upside down and squirted some atf/oil mix into the valve and let it soak for a bit. Then I reached into the nipple with my hemostats and worked the shaft up and down. Testing again, the valve actuated and created a a perfect seal.

ECU cleared again and will know tomorrow if its fixed.

 

[LeakySeals]

You keep clearing the ECU, why? Are you hoping to avoid paying for something? Clearing ECU is nothing more than wasting time, if you fix something the CEL will clear on its own. Have you replaced the gas cap yet?

 

[asand1]

Originally Posted By: LeakySeals
You keep clearing the ECU, why? Are you hoping to avoid paying for something? Clearing ECU is nothing more than wasting time, if you fix something the CEL will clear on its own. Have you replaced the gas cap yet?

I live in Oregon, there are no inspections nor are there smog checks. I clear the codes so that I can let the ecu run its diagnosis and see if the condition is fixed. According to the FSM these particular codes do not relate to the gas cap.

 

[Maxima97]

I have the same code P446. Did the code go away? How difficult to take to canister out? Thanks

 

[asand1]

Originally Posted By: Maxima97
I have the same code P446. Did the code go away? How difficult to take to canister out? Thanks

After a 23 mile drive to work at 60mph (~2500rpm)the CEL is still out. There are three 10mm bolts, two hose clamps, three hoses and one electrical connector. I had it out and on the bench in 10 minutes. There is a video on youtube and writeup on Maxima.org 4th gen sub forum.

 

[Vikas]

In general, P0446 test happens when the gas tank is between 1/4 and 3/4. So you need to give some time before deciding if the problem has been fixed or not.