I don't think it is always that simple. I have had to put four computers on my Durango in the last year and a half, not because of the way that I drive it or not doing regular maintenance to it, but because of it was over idling and under idling.
My husband, the first time that we had it replaced, had to drive with two feet just to keep it running, because if he let up off the accelerator, it would die. We paid 650.00 that time.
When we got it back, the alarm stopped working properly on it. It would go off in the middle of the night. Finally we had to disarm it.
The check engine light came on and stayed on. I have had it in the shop for front end work several times. This last time that I had to put my Durango in the shop to get the check engine light off, so I could get it inspected. It cost me 1119.00 and some odd cents. The computer was replaced yet again. The mechanic told me that it was fried.
Then it got to the point that it would just start dying for no reason. It didn't matter if it was idling or doing 75 miles down the highway. At times, it could take anywhere from 20 minutes to 2 hours before it will start and go, so we took the SUV to the mechanic several times, and he tried to get some codes on it, but nothing found. He told us that the problem is gonna have to get worse before he can do anything, or it's gonna have to trip a code.
So we wait and wait. Finally the problem started getting worse, so my husband replaced the camshaft position sensor and the crankshaft position sensor, and it didn't fix the problem, so we drove it to the mechanic shop and let it idle until it died, so he could get a reading on it. That's where the other two computers come in. He has been all over the Durango, probing every single sensor on the Durango, and still can't seem to figure out what the problem is with it.