P0137

My 2000 Buick Regal 3.8 auto. 280,000 kms has exhibited two problems for several months. The first is that at the engine just dies while driving down the road. In almost all cases the engine starts immediately and may run fine for several days. It seemed to happen when the fuel tank was low so I replaced the fuel filter and that problem went away for about two months.
In the mean time the second problem appeared which is that at idle the engine stalls when sitting in park. Again in most cases the engine starts immediatley and again may run fine for several days.
In the past several days both problems have come back.
I have never been able to get any codes from the scanned until today. The code I got is P0137

Any ideas woud be appreciated

This code is saying the Heated Oxygen sensor 1/2 is showing low signal (below 10mV). A huge list of things could set this code: HO2S wiring problem, Dead HO2S, Low Fuel pressure, Bad Fuel injector(s), Vaccum leaks, Exhause leaks, MAF sensor, Water in Fuel...

I suggest you get the Fuel pressure checked because you might need a new fuel pump. Also check for any vacuum leaks and verify that all HO2S are working. You can also try disconnecting the MAF sensor and see if problem fixed, if so, replace sensor.

Let us know how it works out.