Frank,

I don't know if you have a Bosch or a Rex Regina, so I don't know if this helps or not. Even if our systems are different, some of the codes are the same.

I have been battling codes 231 and 221 on my 1995 940 with the Bosch EZK system. The fault description for my 231 and your 232 are very similar.

I went through a similar drill as you, though I did not replace nearly as many parts. I did replace the O2 sensor, and I don't regret it since I don't know how old it was, but it did not help. This weekend I got an Air Mass Meter (AMM) from the junkyard, and I cleaned it and put it on. Yesterday I drove a little over 300 miles, and the Check Engine Light (CEL) did not come on. Prior to this, about 150 miles was the most I had managed without the light coming back on.

So, do you know for sure that the AMM you put on is good, and that it was the correct one for your car? I had mine checked by a component rebuilder, and they said it was okay. It seems they may have been wrong.

With respect to the TPS, I had some problem adjusting mine. I don't know if it is common, but my kick down cable for the trans makes a faint click as the throttle comes off the stop. It sounded just like and electric switch clicking, and I was having a tip in hesitation. So, I tried to adjust it, but couldn't get much result. With a stethoscope, I found that the kick down cable was doing the clicking, and I had moved the TPS completely out of range. That was corrected, but did not stop the CEL from coming on. It seems that the AMM, or that in combination with the O2 sensor might have fixed it. My fingers are crossed.

Charley