I recently replaced the engine on my 2002 Buick LeSabre. Everything was fine and I drove it to work one day and on the way back home the car died - the RPMs dropped, came back up, then dropped again and the car died on the second drop. Each attempt to start the car, the car would start and run about two seconds and then die. I ran DTC codes and got a P0101 (MAF sensor). I replaced the sensor with the one from the other engine (never had a dying problem with the other engine in the car). The car started up and after a second or two of rough idling settled out and seemed to be fine again. Another 100 miles or so (not sure exactly how much but a couple days later) the car died again. Exact same problem - RPMs dropped, raised back up, then died. Same trouble code - P0101. Had the car towed back home and a couple days later, I thought I would try to start it back up - just died again each time after couple of seconds. Took the MAF sensor that I pulled off the first time and tried cleaning it. Put back on and the car is now running fine again. Tried to put the other back on without doing anything to it (no cleaning) to see if it would die but the car is still runing fine, so I don't think the sensor is the problem.

Any ideas here? I'm afraid to drive it knowing I might have to pay for another tow.

 

Good Morning !
Hope you have a happy Thanksgiving.
Can you do this?
Start the car and let sit running for the 20-30 minutes and see if the same thing happens. We need to do this to rule out anything that could be affected by the driving functions.
Also , where do you think the loud click is coming from?
It sounds like it could be a circuit breaker opening. If that is the case it should reset after it cools. If not At this point I can't think of what would click and be OK after you replace the alternator.
If you would, let us know what happens after running in place for the same time.
Something like this takes a little detective work to isolate .

 

Buick P0101 code.

What does that mean?
Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4.0 seconds. Other MAF sensor circuit DTC trouble codes are P0100, P0102, P0103, and P0104.

Possible Solutions
The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:

Inspect for the following conditions:
An incorrectly routed harness--Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components:
- The secondary ignition wires or coils
- Any solenoids
- Any relays
- Any motors
A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 6-12 g/s at idle to 230 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
The barometric pressure (BARO) that is used in order to calculate the predicted MAF value is initially based on the MAP sensor at key ON.
When the engine is running the MAP sensor value is continually updated near WOT. A skewed MAP sensor will cause the calculated MAF value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
A high resistance on the ground circuit of the MAP sensor can cause this DTC to set.
Any loss of vacuum to the MAP sensor can cause this DTC to set.
If you suspect the condition may be related to aftermarket accessories, refer to Checking Aftermarket Accessories in Wiring Systems.