hey everyone i have a 01 neon

i had code p0442 i went and the shop replaced the leak detection pump
and the purge control solenoid..
that was 2 weeks ago

now the check light came on and the code was p0456

now is there another part i need,maybe the evap canister

are the 2 codes mean same thing...
any ideas

is it hard to replce the evap canister is there a thread for it

also the other code is a 1684

 

I don't have my book handy but but I am sure the code is for evap leak detected. So it means there is a leak somewhere. Could be back at the tank, or the evap line running to the front of the car. Could be a leaking canister. Possibly a loose or bad gas cap. Is the shop diagnosing the car or are you diagnosing it and telling them what to fix?. I would pay the shop to diagnose it and fix it right the first time.

The other code means the battery was unhooked or dead recently, or there is a loose connection and it shorted at one point.