EVAP System Troubleshooting & Testing Fuel Evaporative Valve

[TheSkilletHead]

Shortly after changing my MAF, I am pulling 3 new codes from my DME.

P1128 - O2 Adapation bank 1
P1130 - O2 Adapation bank 2
P0446 - Carbon Canister Blocked / Full / Etc.

Recently, I have replaced:
MAF (<100 mil ago)
Carbon canister valve (< 200 mi ago) (tested working today using Durametric)
AOS (~15,000 mi ago)
Bank 1, 2 Pre-Cat O2 sensors (~15,000 mi ago)

I have some theories as to what may be causing this:

1. Worn fuel cap. I have the most recent revision (#.#.#.03) , but the O-ring is dry-rotted and cracked. I will remedy this tomorrow.
   
2. Bad fuel evaporative valve.
   
3. Blocked carbon canister lines / bad carbon canister
   

# 1 & 3 are easy to troubleshoot. However, does anyone know how to troubleshoot the fuel evaporative valve using Durametric?

When I click on the fuel evaporative valve activation (vehicle off, engine bay cover removed), I cannot hear a click coming from the engine compartment. I have a vacuum manometer for syncing motorcycle carbs and was thinking about hooking that up with the vehicle running, but I'm unsure if the Boxster vacuum will be out of range -- I don't want it to suck up the fluid.

Any advice on how to check the fuel evaporative valve or anything I missed?

[TheSkilletHead]

FYI - answered my question and thought I'd post the answer for anyone searching in the future.

When doing a little more Google-ing, I came across a post by bar10dah buried in the "diary of a high mileage boxster" thread:

Diary of a 1999 high mileage Boxster (links to correct post)

Basically, the Fuel Evaporative Valve is supposed to click when you use the activation on Durametric.

I was able to change the valve today, and the new one does indeed click. When you start the Fuel Evaporative Valve activation it clicks about once every two seconds until you stop it. The click is probably 1/4 the volume of the carbon canister valve. You probably won't be able to hear it unless the engine is not running and the engine cover is removed from the car.

I reset the error codes and will update if the car throws the same codes again, but I am optimistic that this is it.

[Nostril Cheese]

Also check the purge valve on the fuel tank.

[TheSkilletHead]

It's been 100 miles and no codes so far. Checked it with Durametric at 50 miles and it returned no pending codes.

While the car was on jack stands, I changed the fuel filter as well. The fuel filter I removed was on there when I bought the car, 18,000 miles ago & was probably pretty old since the printing didn't match the factory one I installed - it looked like an older design. Because the lean condition was on both banks, it could have been caused by the fuel filter as well, and the P1128/P1130 codes could have been unrelated to the P0446 code --- which is likely based on my understanding of how the Fuel Evaporative Valve works. Either way, I have verified that all the parts I've swapped so far have been bad (even the new MAF reads higher than the old one), so I haven't thrown any money at the car unnecessarily so far.

I hadn't checked my purge valve before and it will be the first thing I check if the P0446 code comes back. Since changing the carbon canister valve, I haven't noticed an issue filling the tank to 100%, so as of now, I suspect it's fine.

[randy_k]

Originally Posted by TheSkilletHead

FYI - answered my question and thought I'd post the answer for anyone searching in the future.

When doing a little more Google-ing, I came across a post by bar10dah buried in the "diary of a high mileage boxster" thread:

Diary of a 1999 high mileage Boxster (links to correct post)

Basically, the Fuel Evaporative Valve is supposed to click when you use the activation on Durametric.

I was able to change the valve today, and the new one does indeed click. When you start the Fuel Evaporative Valve activation it clicks about once every two seconds until you stop it. The click is probably 1/4 the volume of the carbon canister valve. You probably won't be able to hear it unless the engine is not running and the engine cover is removed from the car.

I reset the error codes and will update if the car throws the same codes again, but I am optimistic that this is it.

Glad my Diary thread proved helpful to someone. Best of luck with your car. Mine has been running wonderfully for quite awhile now.
Randy