What the hell is a vent control valve?

[PNYKLR]

Howdy all my friends truck is in for service at Nissan - the check engine light is on the told him it needs a vent control valve
I have no clue what this is - unless its what controls the flow of air into the car(a/c or heat) but I dont think that would cause the check engine light to come on? They want $350 to fix it - I couldnt find the part on autozone online I have no clue what it is they say it sents pollutants into the air and that it slows the engine
down

 

[tjthorson]

Don't know for sure, but I bet its part of the evap canister assemply for venting vapors from the fuel tank so they don't escape to the atmosphere.

A search on the Nissan website shows a 1996 and later TSB on it.

http://www.nissan-techinfo.com/nissan/TSB/Nissan/Truck_D21_EC.asp?mscssid=

 

[PNYKLR]

Thanks dude i still dont know how its possible that it can slow the truck down but who the hell knows - damn foreign cars

 

[soonergn]

I work at an auto warranty company and we see alot of claims for those on all different makes. Not an uncommon problem. I'd say tjthorson is right on.