Originally Posted by Drifter420
Gas cap can cause you to fail emission?
They pressurize the cap, and if it can't hold the pressure (I forget the exact numbers he quoted but I think it was around 20-30 psi) for 10-15 seconds or so, it flunks.
That is significant for OBD II systems (it'll set an error code if the cap is loose or otherwise not holding system pressure, and is such a common fault that they're printing reminders right on the cap nowadays about it), but it'* annoying that they would be bothering to test it for OBD I cars as well. After all, I don't think the '93 has a pressurized tank, does it?
This is the first time I've had a gas cap flunk. Maybe I dropped it and dislodged a gasket or something. Haven't had a chance to look at it very closely yet.