Hello,

I have a 1993 945T with 125K. Just got the codes 2-3-1 and 2-2-1. I'm trying to figure what to do next. The FAQ has info on these codes and indicates that the AMM, O2 sensor, and computer were replaced in order to fix it. I am hoping that all three parts are not what is needed in my case. The car has had the following symptoms recently, although somewhat intermittent:
1) Could not accelerate past ~4500 rpm on freeway, full throttle, (~70mph in 3rd gear). However, if I backed off the throttle, it will accelerate fine to >80mph (at lower rpm in overdrive). Oddly, this symptom seemed to go away when I changed the oil (from 10W-40 dino to 10W-30 mobil-1). (I had used 10W-40 for three quarts while I figured out where an oil leak was coming from (distributor shaft).)
2) Lots of pinging (knocking) even with 93 octane, and just half-throttle.
3) Gas mileage isn't that bad - about 20 mpg on highway with a big load.
4) Sometimes there is hunting idle and stalling on startup. Happens about 1/5 times on startup, and more often when the outside temp is 60-70F.

The distributor cap and rotor were just replaced and the oil leak fixed. Then I drove the car hard, which I hadn't done for a while, and noticed the symptoms above. The next day (after about 300 miles) the codes appeared when I started the car. I have reset them under the hood a couple of times but the check engine light comes on as soon as the car is started and gives the same codes.

FYI: I replaced the fuel pressure regulator, knock sensor, crank position sensor, power stage in the last 2-4 years. The O2 sensor is original, as far as I know. The air filter looks clean. I don't see any obvious vacuum leaks and the turbo gauge is indicating a good vacuum at idle (the same needle position that it has had for 4 years at about 2/5 the way between all the way left and center.)

Thanks,
Steve