just to be clear:
I did a carbon clean, 2 new HPFP’s and installed spacers 2 weeks ago this is when all this started…
I installed 10 new plugs yesterday and 2 new coil packs (one had a tiny drop of oil on it and cilinder 1 since it’s a pain to reach…)
10 new injectors august 2018 (20.000km/12,500 miles ago)
now i’m wondering if i should replace the PCV as well since my intake manifld had a few drops of oil at the intake side in retrospect…
Ok, next step till we get there.
new PCV is in place and tomorrow i’ll replace the gasket of one of the throttle bodies where it pulled a sidestream of air. (as proven with brake cleaner)
hopefully everything will be sorted after this 
So the electrical faults listed well above no longer occur?
In IT, whenever we have a problem, we ask: “What changed?” In your case it was the carbon clean, so your problem is most likely related to that task.
Among other things, you have a few areas you can check:
Why is your car now destroying a cat? The only reasons I know of are a slow deterioration of the cat material, or FOD running through the engine and taking out the cat. I assume this symptom is brand new, but I would not ignore it. You are correct, cats are engine out procedure.
Vac leak of some kind - new engines are extremely sensitive to any vac issues. When you do a clean you disconnect all sorts of vac lines. A smoke test will help you locate any potential issues, but it sounds like you found one already.
Electrical/sensor - like with vacuum, newer engines are also very dependent on good electrics, including voltage and sensor input. The fact that you have so many faults (I did n’t go back and see if the same cylinders were reporting each time - you should do that) would lead me to believe your problem is higher up the food chain rather than a specific sensor or component. (Did you change sparks when you did the work?)
Fuel - is fuel being delivered correctly to the cylinders (I would put this way down on the list) but since so many cylinders are involved on both banks, I am not sure this is a likely candidate.
Finally, though I have not done it with the C6 S6, you can read values with VCDS that might give you clues as to the problem. There are only 3 things required for any engine to run: Fuel, fire and air. Your problem is with one of them, obviously that is an oversimplification.
You need more data, but the air leak tact is a good one to follow.
Ed
i’ve tested with brake fluid while the engine was running that is how i found the leak…
so tomorrow i’ll change the gasket and recheck.
I hope this is the origin of the misfires… so now the faults are still there.
i think the cat might have gotten unburned fuel trough misfires… unburned fuel destroys cats…
After an intake install with the spcers. It’s always a good idea to go back after a few key cycles and check the bolts and check them again and re tighten them as needed. That can help as well.
This was the gasket of the throttle body on the drivers side.
I didn’t even had it off for the carbon clean…
But probably loosened a bit by manipulating the intake I guess…
I hope all will be well when i put the new gasket…
If all the shops are back open I’ll change all the bolts anyway. since I wasn’t blown away by the quality of the longer bolts.
OK so I’m still searching…
Full throttle no problem, the problems come on when the car is idling or doing constant low throttle…
Am I being stubborn ignoring the injectors since the fault came out of nowhere after the carbon clean and they have only 13k miles (2 years) on them?
I don’t suspect that injectors go bad between two starts with a carbon clean?? And all of them at the same time…
Replacing 10 injectors is something different compared to replacing 10 spark plugs…
I’m considering just to pull the intake again and put it back on just to be sure everything is connected good…
However if would be odd to just have misfire codes…
I also have 2 new hpfp’s and a new pcv… But no way to test them I guess…
I noticed vacuum is very strong when I pull the oil cap and the car has a tendency to stall…
Check the diaphragm in your oil separator, if it is ruptured you will get a very strong vacuum in the crankcase.
I am just about to install my spacer now. On the passenger side gaskets, the top gasket (bottom between the spacer and the head was fine) the little holes did not allow the gasket to sit flush. I reamed it out a bit and it was much more uniform. The most likely affected cylinders would have been #1 and #5, so I am pretty sure that isn’t your issue, but leaks will be problematic.
You have already taken care of sparks and coils that would also be likely targets. Your injectors are also not that old.
The only thing remarkable about your data is that 2 of the 10 cylinders (9/10) do not have misfires. (7 out of 10 were misfiring on your pre-reset). The other thing noticeable is a bunch of electrical type faults that ordinarily I would accuse a bad battery of, but I don’t see them in the second list. I think I asked this before but didn’t see a reply: Are all those quiescent and other errors gone?
Since 9/10 are not having problems (in either error list), in theory, you should be able to move things around from there and see what follows what. The only thing to give me pause is you have more misfires after the reset than before, so your errors may continue to spread (or not). Only multiple resets and re-runs of the codes will give you a better indication.
If you are still getting the battery errors I would look closely at the battery and or wiring harness to see if there are any clues there.
The sheer volume of misfires is interesting. There may be values you can log with VCDS that may give you a better understanding of the issue. Also the fact that you spewed detritus out the exhaust is concerning since there is only 1 source for that: your cylinders. However I am not sure that would have led to injectors being fouled.
You also may want to get a camera down the spark plug holes to see what the cylinders look like and if they have anything to say (probably not, but worth a peak).
Ed
I have also considered bore scoping the engine…
My guess is that the junk from my exhaust was Catalyst insulation…
Since junk from the engine will never get past the Catalyst…
But I think my fault is on uw he intake side since it’s just missfires…
I also changed the two hpfp’s but I can’t fault them since I would think it would throw pressure low codes…
I think the early faults were due to the fact that I used the key to turn the engine to close the valves…
So it turned with everything disconnected which was probably not the smartest move…
Only returning error is missfires… I did several resets already! Intermittent and specific cilinders. I changed the intake piece above the intake itself since it seemed warped at one of the throttle bodies.
Is it normal that the missfires and GW faults only occure in ecu 2?
Ecu 1 always reads a fault in ecu 2 and it’s ecu2 that logs the missfires.
If I leave the car at idle or low throttle it will start to cut cilinders.
I want to repeat the car has power it pulls up and above 160mph easy!
Missfires occur on low to medium throttle and full throttle seem to cure them.
I did a reset of the throttle bodies with vcds using the 060 code, this takes only 3 seconds or so right?
Yes Engine 1 gets you stuff like cam sensors and flap motors, Engine 2 gets you some other sensors, but all the misfires show there.
Just out of curiosity, are your dividers in or out of the head?
Not sure about the TB reset, maybe someone else can chime in.
Ed
Do you mean the blanking plates above the valves with the dividers?
I’ve left them out with the re-install of the intake.
now i’ve seen your topic i think i maybe missed a bad alignment of the spacer… i think i’ll just pull the intake again this weekend just to check what’s going on… this thing is driving me crazy right now!
I can’t drive it on a regular base since it requires the room to hit full throttle and rush hour traffic won’t let me…
I’m done with my girlfriends Opel insignia with 140hp diesel engine 
It’s kinda hard to mess up the alignment of the spacers and the gaskets.
Misfires after an intake removal tend to come from a leak at one of the mating points. Check your Y pipe and your intake manifold bolts.
Also make sure to double check the complete VAC and PCV system. Those are two other big spots for vac leaks. Any vac leaks and you’ll see an issue with misfires and low rpm hi load.
You can always check your LTFT data to see if that shows signs of a vac leak.
what do you mean with LTFT data?
all bolts are new and my Y pipe is new as well with new gaskets…
i will recheck the PCV but this is also a new unit.
I did find it odd how hard the vacuum pulled at the oil filler cap…
Long Term Fuel Trim - measuring block inside VCDS. I do not know which block it is, but you should be able to find it on the VAGCOM site.
Ed
Long term trim:
bank 1 is -3,1%
bank 2 is -2,3%
From the first things I found this seems normal…
Can I jump to conclusion that I am facing an engine drop?
Another thing I saw is that there is an option fuel system 1/2 status where it says closed loop using o2 sensors in green so does this mean they work?
Fuel rail pressure (rel): 3400kPa rel
Is this a good value? I do understand my engines but I’m new to the computer /programming part
So, still no sollution here and it’s driving me nuts.
The car still misfires under low (almost stationary) load and when stationary.
Misfires occur on cylinder 1/2/3/4/5/6/7/8 never on 9/10.
If i am at a traffic light the CEL starts blinking after a while so i know this is the time it starts misfiring. Sometimes it gets solved by itself but most of the time i’ll get EPC and CEL telling me i’m no more running on all 10. Just a quick engine off and on will solve this.
If the blinking starts and I put the car back in neutral and rev it af few times the CEL engine light stops blinking so the misfires stop.
If i’m driving hard or not too long on constant throttle everything is OK, engine runs smooth and strong.
BTW i changed: spark plugs, injectors, coil packs, all intake gaskets, the connecting part from throttle bodies to intake, PCV an HPFP’s. Pulled out the JHM spacers for now so i get the car completely stock to search the solution here.
One thing I noticed is that if you check the fault codes i read pressures from 1000mbar to 1010mbar when misfiring at idle…
I would expect these readings on full throttle. Since the throttle valves are supposed to be closed on idle i would expect a lower pressure here or am I wrong?
The miss fire monster is terrible.
If the car misfires often get your vag com ready. If the misfires start make sure to have the engine module open to the code section. When they start hit clear codes. If the misfires stop and don’t come back for a little bit. There are good indications this would be from a bad 02
