| RE:Gas cap question |
Subject: RE:Gas cap question by bogus on 2008/1/13 18:59:32 Good question. On pre-1996 cars, no effect. The vented cap, tho, will vent gas fumes into the air. Those fumes are bad for ground level smog. The unchained hydrocarbons interact with the air and the sun and make ozone. It's the #1 reason why during ozone alerts they ask folks to not pump gas during the daylight hours. When it's really hot and sunny, it makes matters worse. The C4 has a vapour recovery system that consists of a coffee can full of activated charcoal. The gasses from the tank are passed through that and are vented accordingly. That's a simplified description, but it's the basic idea. On 1996 and newer (OBDII) cars, the system is monitored for pressure loss. If the cap isn't on tight enough or otherwise fails, it will throw a code. Won't effect operation, but it will throw a code. |
