Engine has a lack of power?

A new cat helped my car but I had to have the muffler replaced to because some of the catalytic material clogged it up.

2003 ford windstar idles rough, loss of power uphill, flashing check engine light, recently changed fuel filter (gas was clean), new plugs (original code problem), wires look like new (asked local parts store, coil looked good too) still having problems

Its 180,000 miles not 180 sorry

Early in the morning It will start it up and take off with out a problem, But as it starts to warm up it starts to "misfire?" then once fully warm, it bogs out on fast acceleration. If I baby the pedal, it will eventually get moving, but I will have to take the overdrive off so the low speed and high gears will not get the shakes.
I have changed the MAP sensor, fuel filter, checked volt for all air intake sensors. I am thinking coil pack either getting wet or expanding when "warm?" I do not know stretching here.
I read about intake vacuum leak but I do not know about only when hot?
It is my work van and cannot afford to park it to long. Help!

Engine Performance problem
2002 Ford Windstar Automatic 52,000 miles

My 2002 Ford Windstar van runs fine when it's warmed up. However, when I start it up cold, it runs just fine for a minute or so at around 1,000 RPM, but it then drops to around 500 RPM and the engines sputters and shakes and just about cuts off. While it does this, I notice that the battery light on the display flashes a few times. After it sputters for maybe 5 to 10 seconds, the RPM goes back up to around 1,000 and the engine runs fine again. It may do this again slightly a couple of minutes later, but not as bad. After the engine is warm and I get going, there seems to be no more problems while driving or idling. What could be the problem, maybe the alternator going bad? Thanks for your help!

Joe, thanks for your response. The check engine light has NOT come on at any time, just the battery symbol flickering when the RPM's drop to around 500. Once the van eventually warms up, there doesn't seem to be a problem. Obviously something is wrong though, because it's not normal for the engine to sputter and almost cut off a minute or two after startup.

I should also let you know that if I decide to go ahead and drive immediately after startup, without letting the engine warm up for a few minutes, and if I come to an extended stop(more than 30 seconds) at a red light before the engine has had a chance to warm up completely, it'll do the same thing and sputter and almost cut off. As usual though, once the engine has warmed up and the temp gauge is at it's normal halfway point, the problem doesn't occur again.

Are you referring to the Fuel O2 sensor?

I really don't know the last time the engine was tuned up. This van belonged to my mother and I recently took it off her hands. Ultimately that's probably what it needs, a tune up, especially since the check engine light hasn't come on indicating a serious problem.

I guess I'll just take it in for a tune up and have them check the fuel pump pressure. Thanks for your help.

When it is cold acceleration is normal. After it warms up to normal operating temperature it is very sluggish taking off from a stop. After I finally get it up to speed it seems to run okay. Have just put in the best set of plugs I can buy. Did not help.

I first had a mis fire code on cylinder 3, so I changed the plugs and wires, I then had a P01071 code, then both P01071 & P01074, I changed the fuel filter and checked the fuel pump pressure it is 36 PSI. Car ran great for one day, then code P0301 popped up. I replaced the new plug in cylinder 1 and swapped a couple of wires; it still lacks power and is running rough. When I take off it runs rough, then smooths out, but still lacks power

Thank you, I will try your suggestions and get back to you.

Well, as suggested, I checked the vacuum and looked at the lines and intake boot; everything is fin, the vacuum was within the allowances and maintain after the engine was shut off. I did replace the MAF and installed a new coil. My mileage has come back to about 20 MPG on the open road, but it is still somewhat sluggish, the light has come back on and it seems to continue to skip some. Periodically the check engine light will flash while it is running rough, but then it will smooth out and the light will stop flashing. To summarize, to date, I have: replaced the plugs, wires, coil, MAF and fuel filter; checked the fuel pump pressure and vacuum, which have shown to be within manual spec's; checked hoses and intake boot which are okay.

Anymore thoughts?

My 98 ford windstar is losing power after driving it a short while. It will backfire or you hear a sputtering sound here and there. We just changed all the wires and plugs last night and still doing it. The engine seems to be running fine just losing power and will **** lightly here and there. I can let it sit for 5 mins. And it will drive good for a min. Then will start doing it again.