I have a 1998 Grand Prix gtp and was wondering if I need to run a tuned PCM right away. I no it will help the mods but can I get by without it right now. Here is my list
3 inch cat less down pipe
ZZperformance power log
160 thermostat
104 plugs
3.4 pulley
Areo force interceptor scan guage

None of it is installed yet........ Making sure my ducks are in a row