i have an 02 3.0L A6 that's misfiring on cylinder 5. i also have a bad O2 sensor. is the misfiring related to the sensor? if so, can the misfire be fixed without replacing the O2 sensor right away. any suggestions? thanks!

 

More than likely its the ignition coil on a 3.0L, swap one of the coils to a different cylinder and see if the miss-fire changes cylinders. If it does, replace that igniton coil.

 

Thats a great question , can you replace the coil without replacing the o2

 

yes you don't have to replace the 02...unless you have a code for a bad 02 you are fine there. also as long as the 02 is not one of the primary 02's there would not be a issue with misfires....02's can some times lead to misfires but in the end you should look at the coil and then the plug as well if the misfire still is there you may also have a bad MAF....

 

i do have a code for a bad O2 sensor, it's P0050 HO2S Bank 2 Sen 1. i'm not sure if this is one of the primary O2's or not. would this bad sensor have anything to do with my misfire? if so, is it worth trying to fix the misfire first? also, how difficult is it to replace the coil? thanks!

 

The o2 is a primary sensor but is most likly not related to the misfire. Replaced the coil to get rid of the misfire.