Thread: Emissions
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Old 01-04-2021, 09:40 AM   #23
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Join Date: Jun 2014
Location: ATL
Posts: 166

2008 Astra XE
Default Re: Emissions

I did some testing on my purge valve using some human-sourced air supply. First I tried to blow though the valve unpowered, and I could definitely pass air through it. That's not right. So the next test is applying 12V, the valve clicks open, and flow greatly improves. So it functions when powered, but doesn't seem to close fully, allowing "flow during non-purge" as the description for code P0496 would suggest. I removed the valve and shot some electrical contact cleaner through, closing both ends with fingers, and shaking up the fluid inside, then letting it sit. Repeat a couple times. Now when I try to blow through one end, the valve is noticeably airtight compared to before and won't pass anything unless I apply 12V. Fixed?

Unfortunately, the same code came back on the next drive. The valve is either still passing enough air to trigger the code despite my cleaning, or I have a vacuum leak somewhere else.

AstraFasta, your write-up mentioned a cracked boot on the vacuum line running from purge valve to intake manifold. Did your replacement valve also replace this hose with the cracked boot? I am wondering if the hose rather than the valve is my problem. Maybe today I'll try to remove the hose to inspect it for cracks.
'08 Astra XE 5-speed
'72 Chevrolet El Camino
'31 Ford Model A pickup
'69 Lotus Europa
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