I have a 2000 dodge stratus which has 78000 miles and no problems. That is until I changed the spark plugs. I changed only the plugs and used the Mopar wires and the car began to run like crap at idle and now all the time. I have since changed the plugs and wires form Dodge and the car still runs like crap. I get error code P0172. Two of the plugs had alot of blow by on them and I thought this was normal. Is it possible that when I removed the plugs that had the blow by on them, the oil got into the valve and caused my problems? I have tried three different sets of plugs and wires and nothing seems to work. What are the odds that the car was running fine unitl I removed the plugs? I even put the old plugs back in and it did not fihe problem. Please help.