Car starts but stops itself

My 2001 windstar has a problem right now. I can start the engine but if it just stalls when I try to drive it. Sometimes it will stop in front of the stop sign or red light. It has an engin check with code 174/171. Could this the cause? Thanks for your help.

Yes. Those codes indicate there is too much oxygen in the exhaust pipes. This can be caused by many things, but the most likely cause is air leaking into the engine intake manifold. Air leaks can be caused by failed seals on the manifold or from leaks in the various vacuum lines on the engine.

The easiest way to find a vacuum leak (if your a DIY) is to lift the hood and listen to the engine with the engine running. If you hear the sound of air hissing, it's probably due to a leak. Follow the sound to find the leak.