clatter/shaking, CEL on, oil on 2 plugs & coils... diagnosis?

borrowing an air compressor to perform a leakdown test tonight, hopefully i can figure out how to rotate the engine into position (pistons up/down), currently all four of them are at the same level... also going to pull injectors finally to at least visibly inspect.

there's something that's really bothering me at this point though, and it's this... when i finally made it back to the EGR cooler i found it TOTALLY sealed with carbon, as is no flow whatsoever... so how come i wasn't ever getting codes relating to EGR flow thrown, ever? even more troubling, i cleaned the entire egr circuit spotless, and the car doesn't sound any different at all now that its clear... I've read many reports of smoother engine sound but no difference at all in my case. I'm beginning to think my exhaust is clogged further downstream, at the first cat perhaps?

can anyone comment on the weird sound near my throttle body or i take? It is identical to the car in video i posted above. i did notice that when in park my throttle response seems delayed, i can press in the accelerator pedal and there is a noticeable delay in response before the engine spools, does this behavior denote anything to anyone?

 

completed cylinder leakdown test tonight, compression is good in all cylinders... even cylinder 3!

what's next, I am thinking injectors, toying with ordering a set of 4 remanufactured Denso injectors from Rock, and going to start tearing into exhaust from manifold to back of car, not going to be surprised to find first cat in rough shape.

can anyone who has done exhaust comment on what parts I am sure to need when reassembling? I know some of it will break in the process or removal; hangers, washers, etc.?

if anyone can add to my list of things to do/check, please interject and the to all for your help..!

 

hi all, OK sorry for the extended delay friends but I had to walk away from her for a bit, just too frustrating to try to diagnose at this point... trying to muster the will take start taking it apart, again.

last weekend I finally got my fuel injectors replaced, with remanufactured OEM Denso's from rockauto and put it all back together, painstakingly after having to remove the EGR circuit to get at the furl rail safely, started her up,it coughed a little, caught, leveled out and idled fine for about 8 minutes... and then started misfiring and slamming just like before, eventually becoming so violent the car must be turned off as it sounds like its coming apart at the seams. damn. I also noticed as the car began misfiring in earnest a very small rivulet of grey looking water was dripping somewhat steadily from my tailpipe... never seen anything like that before.

after cleaning the entire EGR circuit to spotless, I have so far replaced coils, plugs, injectors, PCV valve, intake gaskets, valve cover gaskets, performed cylinder leakdown test, and spent countless hours disassembling and reassembling the car... invariably, the car will idle fine until the ICE is called upon to recharge the HV battery; once it comes time to recharge, the misfiring begins again in earnest, and soon reaches a point where it must be shutdown... I don't know what this means though... can other parts of the hybrid system (inverter, transaxle, HV battery etc.) cause a Prius engine to misfire? perpetually??

in my reading here on PC I have found one instance where a consistent misfire was finally traced down to a clogged channel in the exhaust manifold itself... can anyone tell me the best way to cross this off the list? laying across the engine block desperately trying not to break the heads off those damn E8 studs by feel alone is not really thrilling, but I'll do it if its the only way...I guess access through the first o2 sensor port wouldn't work to confirm the manifold is clear in all 4 channels? is the fitrst cat being clogged/melted more likely, AND can I gut the cat myself if so? not permanently, but to ascertain if that is the culprit? does this sound like a headgasket issue? thrown rod?? demonic possession or djinn curse???

my misfire seems to only be the cause of all the racket, which I am thinking is actually the dampening plate slamming back and forth against its integrated springs, which in turn is brought on specifically when the HV battery is in a low SOC... can anyone suggest what my next steps see should be, even tentatively?

thanks again for all the input, have a great weekend all..!