Hey guys so I currently have a 06 TL with the check engine light on. Doing a scan at my local Mechanic he says the engine is misfiring. I need to change the downstream o2 sensors and the ignition coils. Now the o2 sensors are something I can do myself but the ignition coils are really tricky. I saw a YouTube video that said to test if your ignition coils are working properly turn on the engine and unplug it. If the engine changes then the coil works. So I did that and the 3 in the back work according to the video but the 3 in the front don’t change the engine when I unplug them. So I decided to swap the ones in the back with the ones in the front to see if they work in different positions. The coils originally in the front work in the back and the coils originally in the back don’t work in the front. I’m not sure do I still replace all my coils anyway or is there a different problem I’m facing?

 

Did you check your spark plugs next?

 

yes the spark plugs are brand new

 

Brand?

 

Did you replace the spark plugs yourself or mechanic?
What brand are they?

Your center spark plug might be cracked. I ran into this issue where front right was cracked and cause misfire on front right and front center, I had dropped it and didn't think it was damaged. I found out the hard way as I had purchase a replacement boot and then a replacement ignition coil.

Check your spark plugs before buying expensive parts. Might be a to get replaced if your parts store is nice enough.