got code p0442 on 2004 Chrysler 300M

the mechanic says I need something like a NVLD or something like that what is that

Asked by for the 2004 Chrysler 300M
2 answers
P0442 - EVAP System Small Leak Detected. The NVLD stands for Natural Vacuum Leak Detection. Sounds like they are saying you need a new NVLD vacuum switch. There are a handful of reasons this code can go off all of which relate to emissions. Loose gascap, A small leak/hole in a fuel vapor hose/tube, and so forth. Generally they'll do a smoke test to find where the leak is coming from, but the easiest thing to check first is the gas cap.

You can find more information at Hope this helps.
he means a leak detection pump. very common failure on chrysler products. you can test through a scan tool. the part is about 149 and the labor is 1 hour.