i have 1996 gmc s15 i have a code p0440 emission control failure how do i repair this problem?

Answer 1

P0440 is a generic code whose OBD II description is "Evaporative Emissions Control Malfunction".
There are several causes for this code, but the one that YOU can deal with is to see that the fuel cap is both present ans secured correctly, and functioning properly.
There are other causes such as a flooded EVAP canister, restricted or damaged purge plumbing, or damaged components such as Purge Solenoid or Valve.
If the fuel cap is not your problem, you most likely will need to take your little pick-up to the shop for diagnosis and repair.
if you have some mechanical ability yourself and want to attempt the repair yourself, secure a repair manual (parts store, book store, library) and read and understand the EVAP system. Then follow the prescribed diagnostic procedures discussed in the manual for this particular code.
Recommend you follow the proper procedures, because otherwise you can stand back and throw a BUNCH of parts at the problem (pronounced MONEY and TIME) and still not repair the cause of the code.
NOTE-----> You don't want to put this off for long, because it CAN lead to other failures, and WILL cause the failure of the emissions test.

Good Luck

Answer 2

most of the time it is from a loose gas cap,evap code.