I’ve searched and searched all the forums to either dead ends or something I’ve already replaced/tested.

My 94 3vze auto decided that on the drive home it would be non stop shaking and stumbling under load. Along with the idle in park at about 725 and in drive 550. It was staying at 900 park 800 idle prior. I have a high amount of hydrocarbons and am registering a lean code 25 only.

I’ve tested the MAF and everything was good just in the higher end of spec like the very edge but I figured it was fine because engine was hot. Replaced cap, rotors, plugs, wires all the good stuff. Chased down lines and they all seem good and In the right spot. Had a huge crack in the air intake boot at the tb but replaced that. Both o2 sensors are reading in spec. And tps was adjusted and is good. Weird thing is with the tps unplugged the park idle moves up to 775 but in drive still drops down to about 550. The timing light seems to be a little sporadic like there’s a miss in only cylinder #1. Because it’s a 3vz I’ve checked the oil for coolant and vice versa and no sign of either. Any input would be great. Thank you 🤘

The turd in question

Cylinder #1 plug. All others looked clean as heck.

 

Looks like a leaking valve seal from here. What does the replaced sparkplug look like now after sitting and running ?

Your lean code is due to the non firing cylinder most likely, if it's not firing it's not using the oxygen which the sensor then reads as lean. It's probably not a plugged injector.

 

I ran it for a day maybe 50 or so miles and as of right now it looks good but it might be too early to tell.