I have no Idea if I'm in the right place or doing the right thing ? But I am Desperate So please excuse me if I'm breaking any rules? I did a Tune up last weekend on my 2009 SS Auto and installed AC Delco 41-109 iridium plugs instead of the 41-108.... Less than 100 Miles later the CEL came on Flashed.... went off so on...... I made it home and the 1st plug I pulled (#1 cyl ) and the tip was Melted even part of the Ceramic was melted or burned off The other 3 plugs were just like new??? I threw my old 41-108's back in and it still misses and the #1 Cyl. plug was wet when I pulled it out in. CEL was off when I made it home but when I did the code reader it said misfire cyl.1.... misfire cyl.2 and I believe random misfires???Oh My Goodness I'm a Decent Mechanic, but I have never owned a Turbocharged engine before!

 

Sorry this Posted before I was actually finished! Any Ideas of what kind of Catastrophic Damage I may have done to my engine? It doesn't Smoke... it doesn't Knock.... It just Misses? I haven't done a Compression Test? anything else I might check? Praying I Didn't Ruin My Motor? So Worried ! Thank You So Much in Advance for anything that might help:)

 

The code reader, what were the actual codes?

process of elimination, move #1 coil to #3 and #3 coil to #1 to see if the problem moves to #3, this would confirm it is that coil causing the problem.
Just breathe, we will get you thru this.

My main question is why install the 41-109 plugs?

 

Must do compression test. Maybe a borescope camera.
Worst case would be the slightly longer plug punched a hole in the piston.

BTW: P0300 is not "random misfire" it is "misfire detected". Another of those misinterpretation things.

 

I just screwed up on the plugs I'm over the 60 hill headed for 70 years old and the older I get the more stupid things I seem to do!!! I do have a Cheap Compression tester but Hoping it might suffice? I've been so depressed I have even lifted the Hood When I got home Monday night I pulled the 1st plug and it was BAD! the other 3 still looked Brand New! So I threw the Old 41-108's and the old coil packs back in it and the thing still misses and when I pulled the #1 plug again it was WET I'm not a real internal mechanic ..... But I have done 95% of my own cars Mechanics my entire Life:) Thank you!!!! Tony

 

I’m 70 and just adjusted to the research before lifting the hood. What kind of wet was the plug? Fuel? Coolant? Oil? Any combination of those? Possibly a head gasket?

 

I looked up both those plugs. They seem to have the same dimensions length wise. Just different heat ranges. Do the compression test and see what you get.

 

I'm gonna guess using the "wrong" plugs has nothing to do with the problem.

Might just be the coilpack connector got damaged in the changeover, or some other relatively simple thing. Swapping #1 coilpack to another location is a great idea. While your messing with it, look really closely at the connector pins etc.

Went back and read the OP. That makes no sense. Burned plug is more likely a lean condition.

 

Well I messed around with it and was hoping to discover something simple...... But didn't figure anything out ? No Matter what I do with coils and plugs #1 Cyl. is Missing I visually inspected the pins and plugs on Coil plugs and everything Looked Good? With key in on position there is power to the plug on the 1st terminal from the left without much variation? I don't believe there is water in the oil??? I looked down all the Spark Plug holes and They all Looked good except #1 Wet on top....... I have to buy a new compression tester that will reach down in there! I actually started thinking that it may be a coincidence in it happening within a 100 miles of an oil change and spark plugs and coil packs being replaced.... I'm Stumped and beyond Freaked Out! No Stored codes after I cleared the po100 and po351 that popped up after I forgot to plug the MAF back in after having the Air Box off well I'm not sure where to even go from here? I will not Panic Yet! I sure as Heck not feeling real good about it? My gut tells me it May be BAD!!!! Thanks Again for all your comments and suggestions and if anyone reads this and has something that might be even a Remote Possibility Please Let Me Know Thank You! Tony

 

Have you checked to see if youre getting spark at the #1 plug, that would determine if its a wiring issue , even that the coils work when swapped just rules out a bad coil, but a bad connection may be the culprit as a wet cylinder is showing unburned fuel. A compression test will determine if a blown head gasket.... can you tell if the wetness is fuel, oil or water?