2000 3.8 S2 SC Stalls

About a week ago my Regal GS started stalling at random. I assumed a fuel problem and so replaced the fuel filter followed by the fuel pressure regulator and finally the fuel pump. No luck...same problem.

Thinking then that it might be a bad electrical connection at the battery I checked the terminations. The positive was loose and so I tighted only to have the post strip out. So I installed a new battery with a new stud. No luck...same problem.

The car continues to stall at idle and at speed. Since replacing the battery when the first stall occurred I did get a service engine light and the code reads P0401. Something to do with the EGR.

As I do not want to continue throwing money at this problem does anyone have an idea of what I should pursue next? :confused:

Remove the EGR valve and clean the valve and the pipe leading up to it. It is possible that both are carboned up to the point where there is not enough flow and that is why you are getting the code. The code you indicated is insufficient flow for the EGR.

Try unplugging the MAF sensor and starting the car to see if it continues to stall. If the sensor is bad the car should run without stalling. If not we will need to look somewhere else for the problem.

Hello,

I removed the EGR valve and both pipes leading to the flange are clear. The EGR valve itself seemed to bind a bit when moved gently with a screw driver so I cleaned what carbon I could at the entrance of the valve. I reassembled and have been driving the car. This seems to have helped but the car still goes through its stalling fits. Drove it yesterday 25 miles no problem. Drove it in the evening five miles and had problems.

Can I use card cleaner to clean the EGR valve?

Where is the MAF sensor? I know that it is in the intake but there are several sensors there.

Thanks for your help.

Penns Creek? What a beautiful location. Good deer hunting.

Use throttle body cleaner. It is not as harsh as the carb cleaner. The MAF sensor is located on top of the throttle body. You should see it when you look at the area where the black tube from the air cleaner connects to the throttle body. It is a weather pack connector and is not hard to unplug. To remove the entire MAF sensor you need a set of torx bits with the hole in the center but you don't need to remove the sensor unless you prove it is bad. It can be cleaned with electrical contact cleaner but I wouldn't do that just yet.

I cleaned the EGR valve with throttle body cleaner. It appears clean and the valve seems to move okay when gently moved with screwdriver.

I removed the MAF sensor and carefully cleaned the platimum heater and sensor with contact cleaner. The heater appeared to have some residue on one side which was removed with the contact cleaner.

I drove the car this morning and it cut out a couple times. On the way home from work it ran fine all the 27 miles.

I have noticed that the outside air temperature indication displayed on the air conditioning controls quite often reads 30 to 40 degrees too low. It could be my imagination but when the car runs fine it appears to be indicating correctly (87 on way home today). Is the same temperature sensor used by the engine management system?

I cleaned the EGR valve with throttle body cleaner. It appears clean and the valve seems to move okay when gently moved with screwdriver.

I removed the MAF sensor and carefully cleaned the platimum heater and sensor with contact cleaner. The heater appeared to have some residue on one side which was removed with the contact cleaner.

I drove the car this morning and it cut out a couple times. On the way home from work it ran fine all the 27 miles.

I have noticed that the outside air temperature indication displayed on the air conditioning controls quite often reads 30 to 40 degrees too low. It could be my imagination but when the car runs fine it appears to be indicating correctly (87 on way home today). Is the same temperature sensor used by the engine management system?

No, there is a temp sensor located in front of your radiator that generates the temp reading for the HVAC control unit. These also fail quite often, but are cheap (<$20) to replace. However, that would have no effect on how the engine runs. There is a separate intake air temp sensor located somewhere in the engine's air intake plumbing. I could be wrong, but IIRC it is located in the top of the air filter box on your car.

I changed the MAF sensor. This appears to have fixed the problem. I need to figure out how to get the CEL off now. I assume this must be reset with a scanner?

I should have read this forum more before "shot gunning" the fuel system.

The MAF sensor was purchased online from a local discount auto parts store for around $120. According to another thread at this site the quality is questionable (Cardone).

Yes, since Cardone sent all it's electronics remanufacturing to China, their quality is questionable at best. Make sure you hold on to your receipt in case it starts giving you issues.

Yes, since Cardone sent all it's electronics remanufacturing to China, their quality is questionable at best. Make sure you hold on to your receipt in case it starts giving you issues.

have you thought of it being the cat coverter? if the maf is good then i would have cat checked.

scrapper, the OP changed the MAF and it's working so far, he's just worried about the quality of the part and whether it will last.

scrapper, the OP changed the MAF and it's working so far, he's just worried about the quality of the part and whether it will last.

ok thanks for pointing that out to me..