Hello, I recently had a condition of no start after refueling. I replaced the evap purge valve and that fixed the no start problem. At the same time I changed all the plugs and coils as well. Now I'm getting the low flow during purge when I reach a 1/4 tank of gas. The c.e.l. stays on until I clear it and then stays off until I reach 1/4 tank again. My car is a 09 cts4 with the ly7 motor and 100,400 miles on it. I do not have any symptoms that I notice while driving other than the check engine light.
497 low flow during purge
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There is a diagnostic procedure for the evap system, do you have the service manual or Alldata? A Tech2 scanner allows you to control both valves and test. Obviously the purge valve is cheap and easy, the vent valve above (?) the tank is hard so you definitely want to diagnose.
Did you use an OEM purge valve? Keep in mind that while unlikely, new parts can be bad out of the box.
I recently experienced P0469 "high flow during non-purge", which was caused by the purge valve stuck open. I was able to see the stuck purge valve pull a vacuum on the fuel tank when I closed the vent valve.
Did you use an OEM purge valve? Keep in mind that while unlikely, new parts can be bad out of the box.
I recently experienced P0469 "high flow during non-purge", which was caused by the purge valve stuck open. I was able to see the stuck purge valve pull a vacuum on the fuel tank when I closed the vent valve.
I do not have the service manual. The part was an ac Delco from auto zone. I was considering that the part was bad.
It's probably a good idea to keep this system working, regardless of emissions concerns. If the vent valve doesn't stay open in response to a purge valve that is stuck open, it applies vacuum to the fuel tank. Causes hard starting, rough running, and could collapse the plastic tank. Just went through this, fixed it in 15 minutes and $25.
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