Scotty I Need help/advice !!!

Toyota Supra 1993 ge
I'll keep the story short
. Blew head gasket and warped head, replaced both and also replaced spark plugs and leads and the car runs perfect no leaking and doesn't miss or any power loss
. Check engine light with code 25 engine running lean happens each time I drive it and warms up and each time I turn the car off and turn the car on again and start driving for about a minute or so the code comes back on but still no missing or no power loss
. Cleaned the o2 sensors overnight in petrol then drove the car for about an hour to get replacement o2 sensors. Removed the old o2 sensors and one is black while the other looks normal. Drove it home and took the new o2 sensors out to check em and the same problem one looks normal and the other one is black.
. Still getting the running lean code so decided to check all vacuum lines for air leaks and did not discover any leaks
Just hunting for some advice please because I'm close to hitting the wall and running out of ideas

Comments
No. 1-2
DRED911
DRED911

Cheers Scotty I'll do that and see how it goes , I didn't put on new o rings on the injectors when I reinstalled them after the head gasket replacement so that prob be a factor to it as well

ScottyKilmer
ScottyKilmer

Editor

well, the black side is actually running rich. Lean codes can pop up as computer tries to make the rich problem lean. realize that. Those old supras are now hell to work on cause you have basically zilch diagnostic data to work on. But in my experience, that's often worn out fuel injectors sending too much gas into the engine. Try pressure cleaning them fiirst