You left off a boost hose. Not a big deal - re-check all the hoses you loosened. For me, it's usually the lower ones that are easy to get to without removing stuff. The wire clip has to be just right or it will feel tight by hand and pop under boost.

 

I didn't remove any hoses. Just the air box, heat shields MAF plug, and O2 sensors. Did the battery reset and cleared old codes. No codes showing, but loss of power when she boosts. I am always able to change my plugs without removing much of anything. I have plenty of U joints, and many extensions. I have a really long Allen wrench that I do most of the coil packs with. I really do need help at this point. I did notice that my engine did not change idle when I removed the oil cap. I'm pretty sure it used to. Need direction for sure now. I didn't mess with any hoses or clamps, but did not see any obvious problems. This sux

 

was gonna agree that you just popped an ic hose or? i did mine a cpl months ago and embarrassingly immediately found my ic hose leak with a loud bang! first freeway onramp lol. it happens. you didn't remove the remove the ic's to more easily get at stuff..? did you remove the liners and heat shields only? double check the y-pipe?

as noted above. it all reads like a simple leak... and yes to the ic hose clips. common issue.

 

I didn't have to remove the heat shield liners, but did bend them or indent them to get things around them a few times. The IC's were not in the way at all. Had to get creative. The driver's side center plug was tough to get to, but I used a reducer, an increaser and another reducer to get the exact depth with the spark plug socket as well. I tape them together with auto masking tape so they don't come apart while pulling the socket off the plug. I tape the U joints also as it makes it easier to get just the right angle. The really long allen wrench is very helpful. I also made a tiny hex socket by wedging the 5mm very short dremeled stub into a small socket and hammered it in tightly. Needed that on the passenger side most forward/front coil pack screws. A couple clips were hard to get to on the coil packs. Mostly went in by feel only on a few. I triple checked everything. She has very similar running problems as b4, but I actually had the original coil packs still at 50K miles and 3 were cracked. One was mega cracked. I sure wish I had a compressor. I have everything else I need to do a boost leak test except a dang compressor. Strange I have no codes popping up.

 

Wait, you are changing your plugs from underneath without removing the ICs??? Can you take a picture next time - I would love to see how you do that. Usually, with a boost leak you will get codes and lights. It looks way worse than it is. (You will only get codes when you should be boosting but you're not.)
If you didn't touch the boost hoses, check the rubber and bands that connect to the airbox. You must be leaking a lot of air from somewhere..

 

I would suggest you check your fuel pressure. The fuel pump has a rubber hose in it that can split over time.

 

It is brand new. I replaced that first. It can rev way up as long as I don't boost. Must be a boost leak unless a turbo has failed?

 

MAF test was perfect on Durametric test AND testing pin 5 was spot on. Not the MAF. Can't hear hissing. Actually sounds perfect until she boosts, then pop and loss of power.

 

Do a boost leak test and report back. A very simple procedure for the process of elimination. You may be surprised at what you will find.
And for the record, you have the patience of a Saint doing a plug/coil R & R that way. Hopefully you double checked everything.
Keep at it ! It's probably something simple staring you in the face.

 

I got out the hose to ear so I could try and hear something with the engine running and it is very difficult to hear as my exhaust is aftermarket and a little loud, but I'm thinking I hear a hiss on the top back of the engine plenum where lots of hoses connect to the T-pipe, behind/past the throttle body. I'm pretty sure I have something leaking back there or a faulty valve. Can't see well enough to find a crack in a hose. I really need a compressor. I would love to do a boost leak test, but no money to buy a compressor at this time. Zero income for a long time now with the virus and my business has been ordered closed. I can probably rent one. Yep rickw30. I did need a lot of patience trying to find tool fitting combos to get to things. Hands are pretty scraped up and forearms had the wheel liner digging in while getting at the front to the car passenger side plug and coil.

 

Do you guys know if a 6 gallon electric air compressor is big enough? On sale at Ace right now.

 

That will do it !

 

that's exactly where the infamous #16 check valve is located, and when it's cracked ( its plastic ) it will often "hiss" as air escapes. but i don't think you'd be able to spot/hear it without a proper boost leak test. e.g. it's not "loud" enough to be heard over an idling motor per se..

 

Yeah, you can't really do a good boost leak test with the car running.

 

Ordered the compressor and hose. I'll report back in a couple wks when it all arrives. Thx BTW. Does the Durametric show fuel pressure? I doubt it and I haven't seen it on there but thought I'd ask. Also what is "Normal" fuel pressure on 996 Turbo?