im getting misfires on a 2005 cadilac cts 3.6l on cylinder 2,4,and6?

[LorraineRe]

at first i only got a mis fire on the #2 cylinder the car has 116,000 miles and has never had the plugs changed so i changed them. since i did'nt know where the #2 cylinder was i swaped the coils from the 2 cylinders that could be to see if the misfire would change to a different cylinder. at first it seemed like the problem went away but after test driving it the mis fire came back this time on the # 2,4,and6 cylinder. under load it does this most between 2and 3k rpm. in park as well but when you accelerate to the rpm limiter (about 4k rpm) it stays perfectly smooth as well as at idle. i thought it could be the 02 sensors but i could only test the pre and post o2 sensors on the passengers side and the post 02 on the drivers side. not sue what side 2,4,and6 are. any help would be great.

 

[Humveetech]

Oxygen sensors won't cause any cylinder to misfire at all, only cause the vehicle to run rich or lean & that will also set a code.

How to tell which cylinder is Bank 1 or Bank 2 is easy.
Look at both front valve covers. You may to lean on the car (Make sure engine is off) Look to see which valve cover is sticking out past the other one. The one that sticks out further is Bank #1 which has #1,3,5 cylinders. The other one that isn't sticking out further is Bank 2, is has #2,4 & 6 cylinders. Of course #2 is the first one.

This miss, I am impressed you did what you did. This miss, which one is incrementing the most??? There will always be symphony missfires what we call, sort of like symphony labor pains the male gets when his wife is pregnant.
Look for the one that has the highest misfires if you are able to look at History misfires. Not sure what scan tool you have, but the one I use--Tech 2, it shows Current Misses & History Misses. I know on some cars, you may have 4 cylinders with 50 misses, 1 cylinder with 500 misses & 1 cylinder with 50,000 misses. Go with the 50,000 misses cylinder. The 500 miss cylinder is generally the symphony cylinder or the one that fires right after the cylinder that is actually missing. The PCM is trying to compensate so that is why it bleeds over to the next cylinder. But if they are extremely close together as for in miss increments, you may have a different issue such as head gasket if they are adjacent to each other, other no power or ground if they are a complete bank is down. You wouldn't have those numbers of misfires would you???

Most of the times, under load with the Caddy's I messed with like the Devilles, it is always the coil pak.

I also forgot to mention, check your oil level!!!!!
If it is low or not on the dipstick, it will also cause some weird issues.
CTS are notorious for using oil & customers bringin them for all types of Check Engine Light issues which the first thing I check is the oil level & 99% of the time, it is not registering on the dipstick. Always check your oil level at fuel fill-up

 

[Humveetech]

Oxygen sensors won't cause any cylinder to misfire at all, only cause the vehicle to run rich or lean & that will also set a code.

How to tell which cylinder is Bank 1 or Bank 2 is easy.
Look at both front valve covers. You may to lean on the car (Make sure engine is off) Look to see which valve cover is sticking out past the other one. The one that sticks out further is Bank #1 which has #1,3,5 cylinders. The other one that isn't sticking out further is Bank 2, is has #2,4 & 6 cylinders. Of course #2 is the first one.

This miss, I am impressed you did what you did. This miss, which one is incrementing the most??? There will always be symphony missfires what we call, sort of like symphony labor pains the male gets when his wife is pregnant.
Look for the one that has the highest misfires if you are able to look at History misfires. Not sure what scan tool you have, but the one I use--Tech 2, it shows Current Misses & History Misses. I know on some cars, you may have 4 cylinders with 50 misses, 1 cylinder with 500 misses & 1 cylinder with 50,000 misses. Go with the 50,000 misses cylinder. The 500 miss cylinder is generally the symphony cylinder or the one that fires right after the cylinder that is actually missing. The PCM is trying to compensate so that is why it bleeds over to the next cylinder. But if they are extremely close together as for in miss increments, you may have a different issue such as head gasket if they are adjacent to each other, other no power or ground if they are a complete bank is down. You wouldn't have those numbers of misfires would you???

Most of the times, under load with the Caddy's I messed with like the Devilles, it is always the coil pak.

I also forgot to mention, check your oil level!!!!!
If it is low or not on the dipstick, it will also cause some weird issues.
CTS are notorious for using oil & customers bringin them for all types of Check Engine Light issues which the first thing I check is the oil level & 99% of the time, it is not registering on the dipstick. Always check your oil level at fuel fill-up