So I have had the CEL, MIL whatever you want to call it 3 times in the last few weeks. I have checked and found codes P0442, which indicates a small EVAP system leak. This would be most likely the fuel filler cap or the fuel filler tube, according to what I have read here on TS. I have also found the procedure for testing and troubleshooting the EVAP system (EG048-04). This is a really great procedure but I don't have all the fancy shmancy test equipment that you need to perform the procedures properly.
So what I am wondering is can I use a vacuum pump/tester to isolate the problem? Can I disconnect the line at the solenoid valve (or connect up to the test port) on the intake plenum (EVAP VSV) and apply vacuum there, while disconnecting, capping, listening for leaks, etc., elsewhere in the system? Is there a possiblility of damaging anything by doing this? What about applying pressure (a few psi) and using soap to locate the leak?
Or should I just replace the cap, then the filler tube if the cap doesn't solve the problem? I'm not one to just replace parts without knowing what the problem is.