06 Si Glen

I have a 06 civic si and just recently my car would die out on me everytime I pushed in the clutch or try to die out when even not in gear. I come to think it's a bad ground but unsure where to start checking or to look for. I've switched both battery and alternator and both have passed test multiple times. Also it starts fine the first time but afterwards it when I go to start it again the instruments flash at me and it doesn't start like it should. Any suggestions