Nissan Repair: Sentra 2001 check engine light., canister purge valve, sentra 2001

Question
My sentra has the check engine light on constantly.  I took it to the repair shop and the diagnostic was my EGR canister was bad.   Replaced it and all components along the path and had them clean out all the hoses twice and even a new gas cap.  the check engine light still comes on and the codes are still the same.  The funny thing is that there are times when the check engine light goes off for about a week or two then it comes back on for several months.  Is there anything i can do to make it stop?

Answer
Dustin,

If it is the EGR valve code I would check the wiring since you have had the path clear.  If it is the canister purge valve code you are probably looking at a loose hose clamp, a rotted hose, there was a recall on some Nissan cars for this, or you are topping the car off too much.  If the car gets overfilled the canister gets too much gas in it and throws a code.