Toyota Repair: Check engine Light and 135000mile service, scantool, trouble code

Question
I have a 2000 4runner and the Ck engine light came on so I had it looked at and I replaced the H2O & fuel sensor . I disconnected the battery and fuse for the computer to clear the ck engine light but it comes back on . the car runs fine getting 23-24 miles per gal. hwy. Is there a code that has to be entered to clear computer ?And also what does the 13500 mile service entail for this vehicle and what should the cost be ? Thanks

Answer
I need to know what the trouble code was and which O2 sensor was replaced before I can help, in some instances disconnecting the battery and pulling the EFI fuse is not enough to clear the DTC and a scantool has to be connected to clear it. I don't answer maintenance or repair cost questions because of the wide variation in labor and parts prices depending on location and who does the repair.