i just bought the car about a month ago .I also had a code of missfire #3 fixed that .the car has 183,000 miles and the moter 60,000 I have no idea what the guy did to it .there was a exust leak i fixed that .not sure if that was it .well i realy dont think that is it .it has lost alittle power.I am going to change the o2 sencers when it warms up .hopeing it is that .can the car lose power from the o2 sensor.thanks