I pulled my code this morning on my 98 GS-R & the light came on for like half of a second, and then went off for a second, and then back on for half a second. I'm assuming that it's repeating itself, which would indicate that it is the Oxygen Content. My question is, is it code 1? The air filter had been replaced at 52k & I replaced it now at 56k but the light is still on, even after resetting the ECU.

 

If it blinks 1 long and 0 short, then it is code 1. PRIMARY O2 SENSOR. See if you can find a friend that can let you borrow his just to see if yours is actually bad.