OKOKOK Ive searched and searched and searched, Was hoping for some info befor i dived in

I have a 90 4runner 3.slow automatic 4wd,

I recently bought this truck and the hole top in was rebuilt at 219,000 and its only got 227 on it now. i believe the previous owners replaced all the injectors for there was a bag of them in the back.

After the truck warms up and i come off a hard pull I.E. driving in the mountains hilly windy roads. When i back off the accelerator the CEL comes on code 25, and 26
Now there is no cat and no stock exhaust so I'm not sure it the o2 sensors are getting bad readings because of it. Im not even sure if they are hooked up. but my light is not on all the time and usually goes out in a couple min (except this last time)

any help to lead me in the right direction would really be apreciated .