It only has one o2 sensor. Lean bank1 is the default language for lean exhaust which is all it knows with only one o2 sensor. The truck is now fixed. With the computer replaced we were able to get a data stream, and from that we could see that the new o2 sensor was bad and only going from full rich to full lean. Replaced the o2 sensor and all is well again. Thanks for all of your input!
did you pull the timing advanceplug before timing? loose timing chain?
David M wrote: ...
OBB I - 1 sensor per converter per bank. So two banks, but one converter, one oxy sensor. Two banks and two converters, two oxy sensors.
OBD II - 2 sensors per converter per bank. Oxy sensors check exhaust ahead of the converter and then after the converter. Thus the efficiency of the converter can be validated and if a problem is detected a check engine light is lit.
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