i started up my 01 chevy zr2 this morning and it started up rough and i went to my buddies house to pick him up for school... and i was sitting in his driveway and it felt like a miss fire but it wasnt IE: no error code. the i go to pick up my girlfriend and i shut off my blazer and she walks out i start it up and i heard a mettalic pinging or bangin please any help you can give me will help i use this blazer as a daily driver and it is my only form of transport an help will do

 

Start with cleaning the egr valve. When it gets dirty it can cause weird idle and make a clicking noise. Get the gasket with a screen in it.