It's weird but my SES light is coming on every 1000 miles, I just disconnect the battery for some hours and the light go off, but 1000 miles more and it's ON again, what would be ? I don't want to PAY $125 dlls to my stealership just to check the codes stored on the ECU, any advice ?
By the way my car is a 2000 I30T ! Thanks !

 

Try this: http://vbxmaxima.8m.com/ecu.html

 

I have a 2000 I30 and I don't think that "turning the screw" method works on your I30. You need to go to the place where they can pull out the stored code for free such as Autozone, or buy an OBDII scanner and pull our the code yourself. I have a similar problem and bought a "code reader" off ebay at around $60 shipped and it works fine.

By the way if the code stored in your ECU is P0420 there is a TSB on it and may qualify for a warranty work. Apparently it involves ECU reprogramming and/or replacing a catalytic converter.

 

well my SES light has been on since I bought my car (about 6 weeks or so) and I just got done trying the turn screw method. It gave me the codes like in the DIY diagnosis but when I tried the ECU decoder it said "undefined" for both of my codes. I did double check and I did write down the correct pulse codes. Here they are:

07-08, and 03-13

The decoder must be different for the infiniti's or something, maybe because we have more options on our cars. Does anyone know where I can get the correct diagnosis for my codes? However the DIY did work to get the codes and to turn off the SES light. Thanks for any help..

 

From Haynes Manual:

07-08 - P0159, Downstream oxygen sensor circuit slow response fault

03-13 - P0158, Downstream oxygen sensor maximum voltage monitor fault

 

hasei, thank you much! Guess I need to get myself a Haynes.