My friend has an 89 Volvo 240 GL. It runs good then sometimes it will shut off while driving, it also happens when the car is at a red light or stopped in traffic. The idle will go from 400 to 1200 rpm on the tach. I checked the codes and came up with 2-3-2 (fuel system compensating for rich or lean air/fuel mixture at idle, and 2-1-4 (speed sender signal missing or sender faulty).

Prior to this problem it had an exhaust leak at the flange and exhaust manifold. He drove it for a couple of months or so. The plugs, and cap/rotor were replaced, and checked all the plug wires. Number 3 plug wire needed replacment. Also replaced the fuel pump relay. I check the AMM/MAF sensor, while the engine was running, it ran bad, but plugging it back in, the engine began to run fine (other than the high RPM at idle).

I checked the Bentley manual, but it does not really explain what to check for. Would the speed sender cause this problem, because of a leaky fuel injector, 02 sensor? Any help would be appreciated.