My Taurus has started to buck a little when going uphill. The tach or speedometer doesnt change and the CEL hasn't come on. Yesterday when the A/C compressor kicked in while it was idling the car died. It started right back up though. I am at a loss as to what to check. The car has 223000 miles on it and has never had anything done to it other than alternator change out, and normal filters changed. Thanks for all of your help

 

Not knowing what "nothing done to it" means, there could be a good possibility the battery cable post connections at the battery and at the engine require some cleaning. If the system voltage drops low enough the computer shuts down and the engine quits running. Just about "always" that is the first thing to check.

 

I'm sorry but nothing done to it means that other than oil changes, air filter changes and other things like serpentine belt change nothing else has ever been done to it. I did change the alternator once and the coil pack once.

 

What about the spark plugs ? If you haven't changed them in a while consider going with Motorcraft plugs. You can get them at just about any auto supply store. Don't forget to set them for the proper gap your vehicle specifies.

Fords will run with anybody's spark plugs, but run best with Motorcraft.

 

I cleaned the battery terminals and changed the spark plugs. Within 5 miles the CEL came on and the code according to the guy at Advance was for the Oxygen sensor post catalytic converter. Of course there are two of them and he didn't know which one it was. My question now, is this normal for the oxygen sensor to show after changing plugs, or is it just a bad coincidence? It is time to change the air filter and I will do that this afternoon. It still runs ok as far as I can tell. I drove yesterday for about two hundred miles and it didn't buck or surge anymore at least. Is there any way to check the sensor to see which one it is or should I just change them both. They are 69.00 each. Thanks in advance

 

If you get the code Advance found, we should be able to help decide which sensor is involved.

 

I took it to Auto Zone yesterday after work because they do a better job in my opinion and the code was P0174, fuel trim bank 2 condition. The ECM has detected a rich or lean air/fuel mixture on engine bank 2. They gave me a list of possible causes. I did change the air filter since that is the only thing for routine maint. that hasn't been done lately and one probable cause they had listed was MAF sensor fault. The filter was extremely dirty. Thanks again for your help.

 

Until we get more info, a MAF sensor problem will not affect only one bank, which is what they stated. It will affect all cyls and both banks, so rule that out.
Bank 2 is the side of the engine closest to the firewall. As chance may have it , could you have dislodged a hose or anything on the firewall side of the engine when replacing the plugs? That is what usually happens when you didn't have the problem before changing the plugs.

 

Thanks I will inspect the firewall side of the engine and see if anything may be loose. I will get back as soon as I can get it done and let you know what I find.

 

I did find a hose loose that was supposed to be attached to the tube between the air filter box and the intake manifold. It attached right at the MAF sensor location on the back of the tube. I reattached it and the car did seem to idle a litttle smoother. I didn't see anything else loose.