HiCustomer Thank you for asking your question on Just Answer.
Did you get a specific error code that you can pass on to us (letter and numbers)?
Did they clear the code, and now it has come back?
If so, is it possible that you could run down there again and have them read the code and write it down?
Hi again. Sorry about the delay.
I was asking about the "clearing of the codes" because it generally takes at least 3 times of the diagnostic tests to be run and pass before the check engine light will be turned off by the cars computer. There will be a history code stored for about 40 cycles (before that one goes away). That is the first time I have heard about a $10K fine. Maybe that is just for the parts places. Most service department procedures have to clear the code as part of the procedure so we can see if the problem HAS been fixed.
Here are the generic descriptions of the codes you mentioned, and a couple more from many GM cars. Not all of these apply to your Sunfire (I only found the three you mentioned in my Sunfire list). Since you have the GM manual for the car, I won't go into the details of each one.
P0440 Evaporative Emission (EVAP) System P0442 Evaporative Emission (EVAP) System Small Leak Detected P0443 Evaporative Emission (EVAP) Purge Solenoid Control Circuit P0446 Evaporative Emission (EVAP) Vent System Performance P0449 Evaporative Emission (EVAP) Vent Solenoid Control Circuit
And here is a routing diagram of the system hoses and components.
I have found that the "small leak" failures usually trace back to loose or damaged hoses, while "performance" failures usually trace back to one of the solenoids. But this is a very generalized trend. Each system has to be examined, and sometimes given "the smoke test" where a "smoke machine" and pressurized air is used to find the leak. Otherwise it is guessing. Solenoids get damaged more in areas where there is a lot of salt and chemicals used on the roads. I have even found wires pulled loose after someone has driven through the woods!
Please feel no pressure to accept this answer unless it helps you. Please let me know if you have more questions.
Take Care, Greg A.