Hi guys having trouble with my car. When I start the car rpm are steady then the check engine flicks on rpm drops then it goes back to normal and it repeats until it turns of.also while check engine light is while driving the trans gets really laggy and when switching gears it's really ruf

 

Does your civic idle high then go low to where your engine has a hard time staying on?

 

It doesn't idle high but it does idle low and turns of

 

My 03 civic, engine light came. Never flickered. But my idle high then went low and stalled. Spent over $400 in mechanic diagnostics. Then come to find out it was my egr valve. I replaced it. And my car ran great since then