2002 Running Rough at start-up and idle

Van started misfiring a couple weeks ago. Scanned error and it was P301-Cylinder 1 misfire.

Changed Spark plugs and it no longer misfires but it is running rough at start up and idle.

Scanned again and new code is P0156 bank 2 sensor 2.

Do I need to change a sensor? Or, is there another issue causing this error?

Please help!

A common failure on the newer (1999 and newer) windstar is the coil pack.

A downstream (past the catalytic converter) sensor is not going to be the cause of a misfire.
The downstream sensor only monitor the catalytic converter to make sure that it is working.
It is possible that something is up with the converter, but it is less likely a cause of the misfire problem.

Another thing to try is the fuel filter and also run a tank of fuel treated with Berryman's B-12 (metal can) to clean the fuel injectors up.

Thanks Wiswind.

I changed the fuel filter this weekend and I am sure that hadn't been done in a while, but its still running rough at start up and idle. I will check the coil pack.

For the 3.8L 2002, where is the coil pack located? I was looking yesterday and following the cables and it looks to be mounted just under the wiper assembly in the middle.

Thanks

That is correct. If you remove the cowl it'll be easy to access and replace. Check the wires too. If they're old, I'd put in new ones just to be safe while you're in there.

Be sure to connect each the wire to the correct terminal on the coil pack.

after doing all that an confirming that the coil is good you may want to take a look at your idle air control. While you've got some specific codes, a dirty IAC is a common problem which is easily addressed.