Weather was crummy here in the northwest today so I was out in the garage running some diagnostics on the wifes 90 740 b234.Code 232 always comes back after 200 miles after I reset the system,I have resealed the intake and injectors and cleaned the throttle plate with no improvement so onto the o2 and air mass meter,with a warm engine the voltage is 2.55 at idle between ground abd term #3 which is higher than the 2.30 spec in the FAQ section,when I unplug the sensor the engine rpm speeds up to 1100 rpm and smoothes out.This is could be indicating a lean condition,even the O2 sensor remains at .80 volt when this occurs probably due to a limp home setting,most of the data I can find on these units is gray for diagnostic.I will give feed back when I replace the unit,it has 170k miles on it and the airbox t-stat was removed years ago and the O2 resonds to fuel pressure increases and vacuum leaks when I create them.Also fuel pressure reg unit recently replaced on last tune-up.
Scott- black 89' 740TC and white 90' 740gl b234