I’ve done a lot of reading, but would like some advice on my 07 is250 with 135k miles.

12 hours after I bought the car I had a p2757 code (torque converter clutch solenoid stuck off). I reset it and drove 200 miles before it went off again. Previous owner must have known it was somewhat intermittent and got it to pass smog (CA) and sell it to me before it threw a code. Butthole. Car also shuddered randomly.

I read through the forums, replaced two trans solenoids: SLT and SLU, I kept a track of the amount of trans fluid and replaced with WS Toyota fluid. Also replaced the trans filter. Oil was dark but still red, nothing alarming in the pan.

Car started shuddering more and then threw a p0894 code (transmission component slipping). won’t go past 4th gear and I have a burnt smell after driving it now.

I’m stuck at where to go next. I don’t know if it’s a ecu/tcm issue which is doubtful, a torque converter problem or the trans itself.

At 135k miles if the trans gets dropped for the torque converter I figure I might as well do the trans itself.

Any help/insight would be appreciated greatly. My instincts tell me the trans is done at this mileage, and I should start to look for something with low mileage.