The taco needs some help

Hi, i recently got a code 2a00 which is referred to air-fluel ratio and the next day my transmission decided it didn’t want to engage in any gears. Altho it would try to go to park but still wouldn’t engage because of a grinding action. I check the trany oil and its perfectly clear. Anyone had the same issue happening. I Did some research and it could be related to a bad ecu but cant be sure yet.

Truck is a tacoma auto 4x4 v6 3.4 2004 bone stock

 

Does your code have a typo?

 

Sorry no typo but it’s basically a o2 sensor reading a bad air-fluel ratio. Or possibly the sensor it self is bad but now that the transmission is not engaging right after this make me think that something else is happening.
So Im wandering if the pcu is affecting the transmission engagement or it’s just purely just cable action?

 

Concentrate on code first

 

Front O2 sensor “generally “ controls air fuel mixture especially upon start up/idle

nothing to do with transmission

 

Ok maybe they are 2 separate issues, i just know the ecu is responsible for the air-fluel ratio but im wandering if the pcu which is part of the ecu is affecting the transmission. Anyway what could be the cause of a transmission not engaging in any gears but grinding when trying to go into park? Even when putting into park when the truck isnts running is still in neutral.

 

For the DTC I'd be looking for vacuum leaks or maybe an exhaust manifold leak.

For the trans, @gearcruncher

 

Possible but
Rather install $69 O2 sensor and then go from there

my 227k mile forester had same issue
Put into P and could roll car back and forth…..would not move in R or drive
Left it in p/l….next day came back and drove home
Happened one more time(stranded)
Had to get rebuilt tranny $3k
Shop owner showed me the drum clutch pack (like a bowl with metal fingers extending from the base)
A full mm of metal was worn away from outer sections of drum from 200k miles of shifting from P to D to R

how many miles on tranny?
What’s condition of red tranny fluid?

 

Thanks the trany fluid is as clear as it gets. No idea of the millage all i know is that it was swap with a the engine in 2018 from a doner truck but i have no record of the mileage from it.

 

U know why engine swap needed?

I’m inquiring bc if an engine overheats….badly….sometimes overheats the connected tranny
Not catastrophic to tranny, but definitely cuts down life expectancy of the heated transmission

 

The trany and engine was swap at the same time but i have no other info since it was 2 owner ago

 

Super weird i started to play with the 4l and i could only put it on while the truck was turned off because it would grind and when i started it the gears were back. But wft happened…?

 

Sounds like you smoked your rear diff
If the transmission grinds when you try to put the transmission in park , this tells me your transmission output shaft is spinning .
Have someone safely look to see if your rear driveshaft is turning in 2 wheel drive with the engine running
The reason your truck moves in 4x4 is because the front driveshaft is now driving the truck .
You, my friend have an issue with your rear differential or rear driveshaft

 

Interesting and accurate ^^^^
Let everyone know what transpires