Chrysler Repair: 2000 Sebring wont catch and run, engine cranks, exhaust gases

Question
Hi,
 I recently bought a 2000 sebring convt with a 2.5l v6 and 120,000. It has started fine but ran a little rough with the idle speed varying from 700rpm to 1500rpm in drive. Sometimes the idle was smooth other times not.I had meant to replace the plugs and wires but haven't yet gotten to it. I let the car sit for a 3 days and now it won't start. I'm in chicago and it's about 32F with some snow. It has started when it was colder then that. I have used a code reader and it shows no DTCs, though the non-continuous onboard monitoring shows the oxygen sensor heater monitor as failed. Will this typically prevent a car from starting? I've removed a spark plug and it looks good, but with a slight smell of gas. When the engine cranks I get spark though it looks a little orange in color. I can hear the fuel pump operate for a second or two when I turn the ignition on. Any help would be greatly appreciated. You guys are great.

Answer
Hi Steve,
The oxygen sensor typically won't prevent starting because that item doesn't come into play until the engine is warmed up. With no diagnostic trouble codes we are left to consider items that are not well monitored when the engine is cold and which could affect mixture as you have verified that you have spark. I would look at the egr valve which is located below the coolant filler pipe and next to the transmission control computer which itself is next to the underhood power distribution center ("fuse" label box). The valve is mounted sideways and is connected to a pipe that comes around from the rear exhaust manifold and to the intake manifold. Notice that is has a round top with a vacuum hose connected to it, and the body of the valve is connected to the exhaust pipe connection. Then in between the two parts is a flanged area which if you look at carefully will be seen to have inside of it a rod with a groove that goes around its circumference. That is the valve stem. Often the valve gets gummed up with exhaust gases and thus hangs up ajar. That you would notice by taking a flat blade screwdriver and using its tip to lever the stem back and forth by inserting it in the groove. A spring inside the valve tries to resist the motion of the stem and attempts to close the valve firmly against the valve seat. If you find that the spring doesn't fully bring the stem to the rest position then take some WD-40 and spray it on the valve stem at the point where it enter the valve body. Then work the stem back and forth some more.
Then see if it will start. If not, then I would check that the coolant temp sensor is showing a resistance of 10,000 to 14,000 ohms across its terminals. That sensor is located adjacent to the coolant filler tube. It has a plug which you release by gently lifting a tab, then measure the resistance using a volt-ohm meter.
If it is a lot lower ohm reading, then replace the sensor. Let me know if either of these are relevant to getting it going.
Roland