I purchased a PCM from All Computer Resources (ACR) and it was wrong, so completely wrong for my 5.9 L V8 2002 Dodge Ram 1500 Quad Cab. I followed each and every single instruction for installation. Upon first crank, I hear the fuel pump continually running and the motor won't fire. I waited a second or two, turned the key and finally get it to turn over and the idle seems rough, but eventually evens out. I drive to work the next day, park it, come out later for lunch, nothing. Turn and turn and turn, nothing. Finally after about 10 minutes of trying to pump the gas, I get the thing to limp over and I have to nurse the thing home, shifting into neutral and feathering the throttle while left-foot braking, just to keep the engine from shutting off. Later that night, I switch back to the original PCM, which threw me a P0601 code weeks ago, which is why I replaced it. The truck started up just fine, but it never seemed to idle well. Fuel pump was the first thing I replaced, to the tune of $185. The idle got better, but it still sounded almost like it was back-firing. I can hear a definite, phoof from the exhaust, almost as if it's throwing un-combusted fuel out of the tail pipe. Today I replaced the throttle position sensor, because it's part of the same system. I determined this would be the next logical step after searching around this forum. The idle seemed to smooth out a little more, but it still stumbles under hard acceleration and it isn't back the way it was before the faulty PCM was first installed. Tomorrow, I'm going to pull spark plugs to read them to see if any of the injectors were damaged by the PCM. If I can find a fouled plug, then maybe I'll have found a damaged injector. Does any of this sound sane? Am I headed in the right direction here? Or have I just thrown some money around at the wrong solutions?

Update: 10/24/2011
I replaced the MAP sensor today and the idle seemed to even out a little more. What I didn't mention earlier is that at cruising speed, i.e. fourth gear, the truck begins to shudder and shake. Before I replaced the fuel pump, it was really bad. When I replaced the Throttle Position Sensor, it got a little better. Today when I replaced the Manifold Absolute Pressure Sensor, it got a little better still, but it is still shuddering in fourth gear and the idle still isn't back where it should be. I have ordered the correct replacement PCM from Auto Computer Exchange and I am hoping when it arrives it will bring some sanity back into my situation. The next part I am looking to replace after the PCM if it doesn't completely correct the idle and shuddering is the Idle Air Control Valve. I pulled the spark plugs today to read them. I didn't find any completely fouled plugs, but there were two that had quite a bit of carbon deposits on them in comparison to the others. I'm hoping the faulty PCM didn't fry my injectors, because a replacement set will cost me around $300. So far my parts have run me $185 for the fuel pump, $40 for the TPS, $40 for the MAP, and $250 for the correct PCM.

As a point, I purchased the first PCM that started all of my problems from All Computer Resources. Their website maintained that the part I was buying would work for a 2002 Dodge Ram 1500 with a 5.9 V8, but not a 1998-2001 Dodge Ram 1500 5.9 V8 for the price of around $225. When I completed my transaction and sent them my information they responded back by saying no, that PCM won't work with your application but the one that will is another $139 dollars. I asked them to verify their information first and they responded by saying it should work. Well, we know now that is not the case. When I tried to return the part I was left hanging for nearly two weeks before anyone got in touch with me via email after 4 emails to their "support" link. When someone finally did respond they said there was no "reason" included in my return, so they didn't know what to do with the part. Another week passes before I get a return of my money, minus a restocking fee of $45!!!