SES; 2000 Sentra SE

[annmargaret]

service engine soon light; code P0440. Same code last year and had evaporation emissions vapor cannister & valve replaced. (service done in 8-05)
car to dealer last week: needed new Smart Entrace Control Unit.
Likely that code P0440 a problem again since cannister & valve replaced less than 1 year ago?
Mileage on car: 52,700.
Thanks, in advance.

[mpe235]

make sure there is no rust under the gas cap, this is a common source of leak
also it is not uncommon to replace an evap canister and vent control valve more than once, if it has been less than 1 year or 12.000 miles it should be covered by parts warranty

[annmargaret]

car kept in shop overnight; now given code P0443 (evaporatative purge volume solenoid). Solenoid power circuit & solenoid ground circuit tested manually & electronically-no problem found & normal operation. Codes cleared from powertrain control module and was told car tested & ran normally.

On drive home, approx. 1 mile from shop: service engine soon light back on.

Recommend replacing evaporative purge volume solenoid? Car has less than 53K miles; was recently in dealer for replacement of Smart Entrance Control Unit.

Thanks, in advance

[mpe235]

sounds like you may have a sticking purge control valve for the p0443 code but I am not convinced that this is the same problem for the p0440 (evap small leak) you should have the system tested with an evap smoke machine.
There is a possibility that there may be a crack in the purge control valve