Riddle me these Corolla symptomss

[oldrx]

 

So the trusty 2zz fielder/Corolla is having a bad week. Started shuddering kinda bad on the way to work yesterday felt a bit like a engine mount let go.

Symptoms include shuddering at low rpm above 3000ish goes away, way down on power, exhaust sounds rough, little back fires on decel, running super rich, smelt hot yesterday after being in traffic but temp gauge normal - think it's the exhaust.

Still drive able, but have to keep the revs up. Idles fine.

My leading theory is collapsed cat converter. Kinda wonder about the fuel system too.

Thoughts? I won't be able to pull it apart until the weekend so if it's not the cat I'm hoping for some other ideas on things to check. 

[AllTorque]

Lift bolts? Ignition coil? Air flow meter dirty? Engine light on? Does it VTEC?

[mjrstar]

Start with easy, bang some new spark plugs at it.

[Guypie]

It's unfixable, please donate wreck to my ae101 2zz swap project.

 

 

 

/My guess would be O2 sensor but I'm not mekanik

[oldrx]

3 hours ago, AllTorque said:

Lift bolts? Ignition coil? Air flow meter dirty? Engine light on? Does it VTEC?

Haven't tried revving that high, have only revved it a few times since owning tbh. No engine lights.

[oldrx]

1 hour ago, Guypie said:

It's unfixable, please donate wreck to my ae101 2zz swap project.

 

 

 

/My guess would be O2 sensor but I'm not mekanik

Will probably end up as good for parts only on a year or so when I get a new daily it's pretty rough 

[HighLUX]

My 1zz corolla did similar things and it was a cooked coilpack which was from a cooked from a leaky rocket cover gasket. Do some testing with 1 unplugged at a time and it should show which one is bad

[oldrx]

One coil has a split right down the length of it so thinking this is my issue, many thanks to OS who saved my weekend from pulling the cat 😆 

[cletus]

Have done band aid repairs on coils like that by just going ham with some insulation tape around and round it 

(If it's misfiring because the spark is escaping through the split )

[oldrx]

Yeah tried that but the fit is super tight so can only get one layer of tape on it

[Rhyscar]

Yeah generally plugs/coils don’t ever get replaced on these, could be a few hundred thousands kms old. 
 

Eventually with no maintenance they’ll do a headgasket or run some bearings. 

[oldrx]

Next on list is thermostat that i've been putting off since I got it. I do oil every time my Mrs car has done 5000kms and this is its second set of plugs, were horrible/black, possibly caused by running too cold half the time/dunno

[AllTorque]

Please get 4 new coils. 2ZZ won’t rev all the way until they are warm, so hurry up with that thermostat. Clean your air flow meter.