Acadia Cylinder 2-4-6 misfires melting Catalytic Converter

Any luck with this issue? Having the same problem

well, i have the same freaking problem. but mine runs with just 1,3,5 cylinders. then doing some stupid things like getting the 6th coil pack and pull it and plug it to see the spark jump but nope, no power. but then all frustrated and almost setting the truck on fire just ti get rid of it. i pull and moved the harness away like moving it around and just like that the coil started to spark, i moved the harness again and was lost, so.... i think that is the harness, that is messing around somewhere, either not grounded really good or some stuff. i will replace and post any update.

I am having the exact same issue with cylinders 2,4,6. If you have an answer that would be amazing! It melted the tip off the O2 sensor and the front cat as well.

Check the harness from the fuse block they tend to Reston the bank 2 cat and melt

I was having same issue but actually all cylinders were misfiring and I had a can sensor code for bank one I changed it the service engine light turned off on its own a couple days later came back on now says misfire in 2,4,6 and some kinda fuel code

That fuel code (If it starts with FC ) is telling you the engine is operating "open Loop" meaning the O2 sensor is not being used. This is normal while the engine is warming up. It is NOT normal once th engine is hot. I also have 2,4,6 misfiring .. I hear a lot of unburned fuel in the exhaust pipe detonating , and the engine runs like heck. I've read only one somewhat possible reason , and I have one myself. The common point for 2,4,6 is where the return wire connects to the engine block .. its the same point. So maybe that's loose. Second, I've heard the fuse box passenger side under hood.. has issues over time. I tested this by pulling on the cable while engine was running .. and sure enough .. the engine stopped. on other trys I could get the roughness to stop (presumably 2,4, and 6 had started to fire again). This is the only solid clue I have. There is a fuse for 1,3,5 and a different fuse for 2,4,6. I'm not saying its the fuse .. I'm saying it might be the wire under the fuse no longer reliably connecting.

This is the problem with the forum. There are many problems presented .. but almost no people with answers. You would think with so many Acadias sold .. and since 2007 .. someone should already have this issue and other pattern problems solved & cataloged by now. I'm here so I don't have to be the pioneer ..

Please note .. that fuse (look at the fuse layout on top of the cover to find the correct fuse) will not go directly to the coil packs. instead it will go to the ECU ..

The ground for the coils on the front head had the eyelet crimped around the casing of the wire from the factory not getting a proper connection redid eyelet problem solved. the may have had a run on bad crimps. worth a look

Check engine light came on one day. Hooked up the diagnostics and had like 6 pages of codes with misfires and initial startup parameters not met or failed. cleared and it stayed off for like a month. It has always ran rough when first started but then smooths out. took a trip on another day. stopped at a gas station and the car started running rough. turned it off and restarted and it ran really rough and white smoke out of the exhaust. Turned it off again and restarted and it ran fine. checked everything again and carried on only to find that the volt gage was falling below 13 volts... left it running to check it out and couldnt find anything. Turned the headlights from "auto" to on and the voltage went back up. The engine light has been on this whole time and as long as i watch the volt gage and turn on the headlights when it starts to fall its fine but gotta do something about this... Could the alt just be bad and causing it all???

fuel pressure sensor giving bad or false reading so computer is trying to up amount of fuel sent to bank 2 unplug the sensor on fuel rail and try to run it and see if it stops

Catalyic Converters?