st-162 fault codes

[XiL3D]

hi guys,

my celica used to give me code 21 (o2 sensor) on occasion. i replaced that and now im getting in succesion (right after each other) code 25 then 26 or lean mixture then rich mixture.
i cant figure out whats causing this. i put a brand new k and n panel in so its not that. ive run some injector cleaner through a couple of times. btw the car still drives perfectly with no power loss or anything, smooth as.

im out of ideas, so throw some my way

thanks in advance for any help

regards,
john

[Aust162]

After you replaced the o2 sensor, and air filter did you reset the ecu?

If not, you need to pull the efi fuse out for a few seconds to reset it.After that, then check for codes. hopefully you fixed the problem.

[XiL3D]

ill give it a go