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I was getting misfire codes from the front engine coil packs. So I changed all three out plus plugs.
Ran great for awhile and then started getting misfires again so I had the back 3 coil packs and plugs changed out including the intake manifold gasket.
Now I am getting random misfires. What is interesting is that the Traction Alert comes on during the misfire.
No codes were written and the check engine light went out.
So, at this point, I am going to run injector cleaner to see if that does the trick.
Just sharing the journey.
 

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I recommend Techron Concentrate Plus..
 

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Read about cleaning carbon deposits off the intake valves. Those deposits can cause random, no code misfires. Techron (or any in-tank injector cleaner) isn't always the answer. Look into a good top engine cleaning spray like SeaFoam.
 
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If its sticky valves/carbon buildup on the lip of the sealing surface of the valves- it can cause random misfires.
If the misfires are not severe- you can start using the cleaner now to start cleaning that stuff as you drive.
Like mentioned the top end engine cleaner- either by hand or chemical can be done..... with downtime of course.
 

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I was getting misfire codes from the front engine coil packs. So I changed all three out plus plugs.
Ran great for awhile and then started getting misfires again so I had the back 3 coil packs and plugs changed out including the intake manifold gasket.
Now I am getting random misfires. What is interesting is that the Traction Alert comes on during the misfire.
No codes were written and the check engine light went out.
So, at this point, I am going to run injector cleaner to see if that does the trick.
Just sharing the journey.
For random misfires, you may also might be getting LSPI (low speed Pre Ingnition) if you have fairly high miles on your Acadia, carbon particles can build up around the top edge of the pistons and even down into the first piston ring. These create hot spots and can ignite the fuel charge in the cylinder.

There is a product the BG makes . . BG109 EPR Engine Performance Restoration . . and while primarily to help with oil consumption people report it helped greatly to remove carbon that causes LSPI. Over on the Terrain forum, a member used it according to directions and solved his issues.
Add it to the oil BEFORE an oil change and run the engine at a 1,200 RPM idel for 15 to 20 minutes. Change the oil and filter . ..
For less than $19 it might not hurt to try.
 

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Direct injected engines have been facing issues with carbon build up on intake valves since their inception. This is caused because no fuel is washing off the intake valves as it is sprayed directly into the cylinders. The carbon build up disrupts the air flow causing the misfire. GM even makes a aerosol can of top end engine cleaner that you spray into a vacuum line that will actually make it to the valves to reduce the build up. A decent scan tool that can see live data will actually show a lower than normal idle vacuum reading.

Not saying this is the solution but is definitely a known problem. When getting misfires on a whole bank I would be thinking about what those 3 cylinders have in common such as plugged cat, wiring issues for coils or injectors etc....
 
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