I've been throwing this code for a while... here's the kicker... only when my gas tank is 3/4 or less full
suggestions on what to check? it's simply a piss off to continuously be clearing this code



Buddy Club Ecotec Cavalier
* More to come *

mine does that too, its related to the gas cap. make sure its tight, really tight... go so far as to push inward as its clicking into place. may or may not help, good luck!

The car will only test the Evaporative Emission (EVAP) System or in this case the Purge Flow when the fuel tank is between 3/4 and 1/4 of a tank of fuel . . the 1st thing I would ckeck is the purge valve. and then all the vac. hoses that go to the Evaporative Emission (EVAP) System .

I had a small pinole in the fuel filler tube. Doesn't take much for the system to not build pressure. A smoke test will cost you about 50 - 75 dollars, might be worth it to find the leak.


Labrat

Tech97 wrote:The car will only test the Evaporative Emission (EVAP) System or in this case the Purge Flow when the fuel tank is between 3/4 and 1/4 of a tank of fuel . . the 1st thing I would ckeck is the purge valve. and then all the vac. hoses that go to the Evaporative Emission (EVAP) System .

Well that makes a lot of sense
I could NOT figure out why the capacity of my tank would make a difference :lol:



Buddy Club Ecotec Cavalier
* More to come *

May be the fuel tank pressure sensor, Had one go bad in my gf's Z24 a few months ago and it would only come on after 3/4 tank. I'm lucky enough to own a Tech2 so I was able to manually open and close the vent valve (which was good) and watch the voltage of the fuel tank pressure sensor as it was reading 0.0 volts all the time. The fuel tank pressure sensor voltage at empty is 0.0 volts and at full should be at 5 or close to 5 volts.

If you are sick of clearing the code, why not fix the problem.

Sometimes, as with my vehicle the purge solenoid was not working.

Removeing it, applying 12V to it, and it didnt click. Replaced that the problem was solved

Could be a leak as well

The whole gas cap thing above is stupid,once it clicks thats as tight as its going to get


- 2004 Cavalier - 124k, owned since new

make sure the o ring on the gas cap is not cracked that happened to my brothers alero



JBO since July 30, 2001