I'm mostly interested in why your LTFT is -25%, when it used to be near zero. To me, that says that one of the sensors used to calculate required fuel has changed drastically and the ECU is reading the narrowband O2 to bring AFR back to where it wants. If your wideband O2 says you are near 14.7 at cruise, then the ECU must be interpreting the narrowband O2 output correctly. I am assuming that you have three O2 sensors (wideband, front narrowband, and rear narrowband). I would look closest at the MAP and IAT. You could dig through the electrical manual and find the expected output of both sensors at two points (absolute pressure versus voltage for MAP and temperature versus resistance for IAT). You could then calculate what the raw output means and decide if that is interesting. Of course, you'll look like a nerd, driving down the road writing notes and punching numbers into the calculator. It would be safer and less embarrassing to buy a proper OBDII logger cable that works with a laptop. I might only use mine once every few years, but I never once regretted the purchase.


Corbin
'95 ESI-T

Now with more power and fewer leaks



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