1998 Contour starting and running issues

Maintenance is always good as said. If not, Check for codes in the computer for a direction to go in. Any cel present?

If you're going to change the o2 sensor, a couple of things. First make sure you have a wrench that can get a firm grip on the nut of the sensor, no adjustable wrench. There are a couple of nice o2 sensor removal tools out there, I bought one at Advance Auto Parts, it's an abreviated version of the larger one which wouldn't work on my back sensor that broke, check them out. Secondly, take a propane torch and heat up the flange on the exhaust pipe where the sensor screws in, if it's hot, usually it loosens a lot easier. Stone cold will be a b#$%h to get off. Couple of other easy things to check, the maf sensor and the idle air control valve, clean them both, someone on here will tell you how if you're going to do it.

Great point TW,

Found this along the way:

It seems that a "missing" engine culprit is actually the computer's sensor inside the Mass Air Flow Sensor (MAF). It eventually just gets a little dirty or builds up its own patina in the filament wires. A dirty or slightly patinated filament will send the wrong air reading to the computer, saying it is getting more air than it really is and the computer will tell the EFI to send in the wrong mix of fuel, thus, the bogging. The patina seems to form faster if you live in a damp climate. If you have had bogging or missing or idle spots, about every 25K miles plan on this quick cleaning job:
When your engine is cool, remove the wiring clip from the side of the black plastic sensor part of the MAF aluminum body. To remove the MAF interior sensor wire, you will need a Security Star (Size T15 or T20) screwdriver or screwdriver bit for a power screwdriver. Remove the two security star-head screws and carefully remove the sensor. You will see the two sensor filaments... They look almost like the filaments on a light bulb. Carefully spray the filaments with an O2 safe carburetor cleaner, such as Gumout. Let it dry thoroughly. I help mine along with a careful blast or two of canned dry air. While it is drying carefully wipe the aluminum mount surface of the MAF body if there is any dust there, but be careful not to get dust in the mount hole. When the sensor is dry, replace the sensor back in the MAF body and secure with the security star-head screws. These don't need to be torqued down, just simply hand tight. Replace the wiring clip. Then start up your engine.

Thanks so much for the replay and solution...wish we could have ha

d the answer.