2000 accord coupe v6 Runs great except when you slow down, it idles & vibrates really hard; it levels out when you put brake on.. The last owner just put in new plugs.. any help for this old lady? Thanks!!Nettsey

 

Normally the oxygen sensor is stressed most when you are slowing to an idle. If it's getting lazy it won't be able to adjust properly. First thing I would replace, assuming it hasn't been replaced lately, is the oxygen sensor. You just need to change the upstream sensor to a Denso replacement.