97 cavalier, valves clatter, power loss, engine chugging

About three days ago my 97 cavalier auto (think its a 2.2), 192K miles began running rough, "chugging" between 500 and 1000 rpms when stopped at a light. When I accelerate, there is a notable loss of power and the valves clatter unusually loud around 3000 rpms. Changed all 4 plugs, (they were BAD). It ran great for about two miles until I stopped when "chugging" and power loss resumed. I deliver pizza but do not drive it hard, tips are good enough without ragging on it. SHould I bother with plug wires or any ideas on other possible causes? BTW: Engine was alegedly rebuilt at 130K miles.

Just a guess ...if motor was rebuilt 60,000 miles ago it probably has not had anything done to it in awhile a set of plugs gave it life for two miles what would a set of plugs (boots) give it.How about an oil check change ,tb cleaning iac check for vaccum leaks or how about a new air filter or FUEL FILTER
It would help if you knew for sure about your car and any thing else that might be going on

Did you use OEM plugs? How about a SES light?

check your fuel pressure!