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

OK... spent yesterday changing valve cover gasket, cleaned EGR up to the valve but couldn't get it or the cooler off, have changed plugs but only moved coils around, no replacements on hand as of yet... started it up today to be greeted by the same awful clatter. as much as it pained me to do so, let it idle long enough to check codes on mini-VCI, and omg here goes the new, improved list...

P0102 mass air flow circuit low
00108 manifold absolute pressure circuit high input
P0113 intake air temp circuit high input
P0123 throttle pedal position sensor switch A high input
P0300 random misfire
P0301 misfire 1
P0302 misfire 2
P0304 misfire 4
P0352 ignition coil B primary/secondary circuit
P0403 EGR circuit
P2135 throttle pedal position sensor/switch A/B voltage correlation

w.t.f.

keeping in mind when this started I only showed p0300, p0301, p0304... what's next step? is my engine shot? is there no point replacing all coils today? could bad gas or ex-gf sabotage give results like this,?

 

the coolant reservoir? the coolant inside is still its usual pink color, it doesn't look oily from viewing the coolant resevoir from my usual viewpoint, should I get some of the coolant out to check closer?

 

hi all, OK... been a while but have spent much of my spare time trying to get this poor car going again, here's a list of what's been done/replaced up till now, and a current description of the issue..:

replaced plugs
replaced coils
replaced PCV valve
cleaned EGR circuit (pipe, intake, valve, cooler)
replaced intake manifold gasket
replaced valve cover gasket & plug grommets
changed oil and filter

OK, so when I got the EGR cooler off finally I found it to be literally sealed off it was so clogged, you couldn't even blow through it... took 4 days of soaking and use of a gas-powered pressure washer to get it cleared... capillaries of intake manifold were very gummed up too. yesterday got the coolant refilled properly and air bled, and fired it up... MIL is gone, idled for 6 minutes sounding normal, then here we go... clatter, knock, bang bang bang. P0303 shows up on techstream three times, have to shut down as it sounds like it's chewing itself to pieces.

still, no coolant loss at all, and oil looks normal, no smoke from exhaust whatsoever, although I have noticed when uncapping coolant reservoir there is a tiny amount of pressure released when I twist the cap... does this put me in blown head gasket territory for sure then? last night when I tried letting it idle the misfiring got bad enough that the car was shaking violently.

whats my next move, is there anything else left to check before getting internal with the engine? could filthy/fouled injectors cause this awful misfiring issue?

lastly, I noticed in my teardown that the inverter coolant seems still and unmoving, unless this whole "turbulence" effect is something so subtle it is high undetectable...

any advice friends? I really don't want to junk the car, but I don't want to beat my head against it or throw good money after bad... I'm willing to try the head gasket myself, am just worried about something being messed up in the bottom end too. thanks in advance all, any pointers would be great, if anyone thinks pulling the injectors to clean would be worthwhile let me know!

 

thanks to you all for the replies... just spent a fruitless evening poking at the car again, dpuble-checking what I could, result has been same as before; fires up and sounds normal, for about 15 minutes this time. I watched the live data from Techstream during this time, that is where I saw the cylinder 3 misfires again.

I tried swapping coils & plugs between cylinders 2 and 3 last night, the misfire does not follow coil/plug, although tonight I did see a misfire register from cylinder 1 (the first actually, but only once), all subsequent, and progressively violent misfires were at cylinder 3). once they really start getting bad I feel I have to shut the car down, they are very loud and somewhat rock the car... I honestly don't know if the effects are coming from the engine, or the dampening plate w/ all the springs on the transaxle slamming about due to the engine motion, it sounds loudest from beneath the car on the drivers side I think.

my coolant level is not going down, nor has the color of the coolant changed...

I also noticed tonight, while trying to determine if water pumps were working or not (still not sure about these!) I noticed a sound I've gotten used to hearing under the hood when ICE is off and car is in ready... it sounds EXACTLY like the 1st-gen in this video..:

I tried to determine where it was originating from, and I'd swear it was coming from either the throttle body or somehow (?) within the intake manifold itself... the much older Prius in the above video sounds exactly the same, although no explanation was put forth there unfortunately.

I will! see if I can get ahold of the referenced tool from harbor freight today, many thanks for that pointer padroo. I have read so much here on the fora I am sti!l clueless to decode my symptoms.

I can add that tonight when the misfiring started up again my coolant temp was only at 140f... the only other thing I could add is that I think most everytime the cacophony ensues the ICE engine is trying to charge the HV battery, which has two weak blocks apparently (7 & 10), but only rarely throws a PA080... I still don't honestly believe the inverter coolant is turbulent or swirling, I see no motion personally but have read it can be hard to perceive... tonight no MIL appeared despite the spate of misfires, it I'm sure if it'd taken it out on the road I would have racked up some P0303, P0301, etc... the again everyone!

 

it was idling nice and normal for a good while (20-30 mins) so i took it around the block tonight with Techstream up and running, hadn't made it a block before the misfiring started up again, first with one misfire at cylinder 1 and then thirteen consecutive misfires at cylinder 3... always seems to be at 3, its not just like the engine is missing, it is violent and loud.

going to try to make it to harbour freight today for the leakdown test kit, hopefully that will enlighten... car is starting to get dusty.

any tips or suggestions as to other things that could cause these misfires would be greatly appreciated, thanks all.