Nissan Repair: cant pass emission, nissan sentra, purge valve

Question
i have a 1997 nissan sentra gxe i need to pass emission the paper says trouble code present p0400 egr flow p0440 evamp control system p0446 evamp control system vent control circuit can i do this myself with the help of a person who knows cars

Answer
Diane,

Yes, replace the EGR valve first and make sure the port is clean before you bolt the other one on.  The second one is more difficult.  But, you can do it.  The vent control circuit is pretty simple.  The canister that catches gas vapor has a vacuum valve that opens and closes.  When you first start up your car the valve opens to allow the vapor to get sucked into the engine and burnt off.  The computer is sensing a problem with this vent control.  I would purchase a canister vent valve (purge valve) and replace yours and that problem should be solved too.  Just a couple of hose clamps and a connector for this one.  But, it is under the car so you will need someone with a jack and jack stands to hold the vehicle up safely.  A Haynes Manual would be great to show you the pictures of the evaporative system.  There is a diagram sticker, under your hood, that shows the routing.  But, it is not the most detailed picture.