2004 tl u can feel the car miss fire but it doesn't give any code for mise firing it only gives code for bad oxygen sensor bank 1 . i just changed the spark plugs to new NGK LASER IRIDIUM Spark Plug IZFR6K-11 # 6994 .. what could be the reason and what can i do to find out or to fix it ?

 

I'd say no missfire if no code. Any leaks in vacuum lines?

 

When does it misfire? just at start up? I would also agree with Turbo and say if there is no code,the ECU doesn't detect a misfire present.

Are you sure it's a misfire,what about a worn motor mount causing vibrations?

 

Did you change the plugs because it was misfiring, or did you change them and now it is misfiring? How long has it been throwing a code for bad O2 sensor? But in general, if it's not running right, and the ECU is reporting a bad sensor of any kind, seems to me you'd want to take a look at what is causing that code, is it really a bad sensor? Replace if so... Maybe the problem you're seeing is a result of a failed O2 sensor. All that beig said, mine just started misfiring (https://acurazine.com/forums/3g-tl-problems-fixes-114/misfiring-889703/).