When you say you have a code 48 does that mean that after you reset the ECU to clear the code, the CEL comes back on right away after starting your car with code 48? Or does the CEL come on at unpredictable instances?
I had an intermittent code 48 on my VX that would come and go with increasing frequency over a three year period. Once the CEL kept coming on every couple of weeks I decided to change the LAF to a lightly used OEM one from a high performance tuner shop and have not had a code 48 for seven months now.
So yeah, it could be that your LAF is triggering the CEL.
it comes on about 35-40 seconds after starting and stays on till i kill the car and then the same thing all over again i tried to monitor it per instructions in tomo s post on that and the reading is always -.77