[Efren916]

How’s it going guys, I’m new to the page and also new to the CTS V game I recently purchased a 2012 CTS V and it’s been a head ache since the get go. I keep getting random misfire codes for cylinder 2 and 4 I changed spark plugs and wires thinking it would be the issue and nothing did a compression test just to make sure the motor wasn’t hurt but everything is good I recently found one of my cats were clogged up so I removed them and misfire went away but recently I borrowed cats from a friend and installed and misfire is back i thought maybe the o2’s were damaged replaced all 4 and misfire still present but when I remove the o2’s and not plug them the misfire goes away at this point I’m lost but the car does have a ported blower and upper pulley I was thinking maybe the car isn’t liking back pressure from the cats but if anybody can give me some info that would be great

 

[Karch]

How’s it going guys, I’m new to the page and also new to the CTS V game I recently purchased a 2012 CTS V and it’s been a head ache since the get go. I keep getting random misfire codes for cylinder 2 and 4 I changed spark plugs and wires thinking it would be the issue and nothing did a compression test just to make sure the motor wasn’t hurt but everything is good I recently found one of my cats were clogged up so I removed them and misfire went away but recently I borrowed cats from a friend and installed and misfire is back i thought maybe the o2’s were damaged replaced all 4 and misfire still present but when I remove the o2’s and not plug them the misfire goes away at this point I’m lost but the car does have a ported blower and upper pulley I was thinking maybe the car isn’t liking back pressure from the cats but if anybody can give me some info that would be great

Please try to use some punctuation, it’s very difficult to read it like this.


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[tramminc]

Check and clean all your grounds. especially the 10mm ground bolt under the air filter.

 

[clarkbekcz]

Most Common Causes of an Engine Misfire

• Ignition system problems. When most people hear the term misfire, they think of worn out spark plugs. ...
• Air and fuel delivery problems. ...
• Emissions equipment problems. ...
• Engine mechanical problems. ...
• Sensor and module problems. ...
• Control circuit problems.

krnt.run
myindigocard app

 

[m13s]

Random misfire - you can't make this stuff up.......

 

[Efren916]

Check and clean all your grounds. especially the 10mm ground bolt under the air filter.

Thanks for the help! I tried this and still didn’t work.

 

[mememe123]

Thanks for the help! I tried this and still didn’t work.

Check grounds on back of both heads, and check injectors, one of your connectors could be loose/disconnected or bad wire

 

[STL V]

How’s it going guys, I’m new to the page and also new to the CTS V game I recently purchased a 2012 CTS V and it’s been a head ache since the get go. I keep getting random misfire codes for cylinder 2 and 4 I changed spark plugs and wires thinking it would be the issue and nothing did a compression test just to make sure the motor wasn’t hurt but everything is good I recently found one of my cats were clogged up so I removed them and misfire went away but recently I borrowed cats from a friend and installed and misfire is back i thought maybe the o2’s were damaged replaced all 4 and misfire still present but when I remove the o2’s and not plug them the misfire goes away at this point I’m lost but the car does have a ported blower and upper pulley I was thinking maybe the car isn’t liking back pressure from the cats but if anybody can give me some info that would be great

Had a similar problem after installing my RPS Triple Disc Carbon Clutch. Tuner was able to track it back to some harmonics jist outside of the factory range due to the new set up. Determined nothing was really wrong but the computer didn't really know what to do with it so it determined the best thing was a random misfire. Tuner was able to do whatever tuners do to make it go away under that condition. Hope this helps. Also as others have mentioned the grounds are super easy to check and can really cause all sorts of weird stuff to happen.

 

[5ft24]

Swap the #4 and 2 coils with 2 other cylinders and see if the misfire stays with 2&4 or if it moves. Bad coilpacks cause issues as well