Oxygen sensors

[CMLJESSE]

What are the symptoms I look for if a 2.5L 2000 Ford Ranger has bad O2 sensor?

Sometimes it has trouble idling (especially with A/C on) and I have to keep my foot on the accelerator for it to idle. I do hear "clicking" sounds under the hood every few seconds or so.

But other times it idles just fine at 1000 - 1500 RPM.

Hmm...just can't figure it out.

[Dave R]

Not sure about the clicking sounds but otherwise what you have described could be the result of a sticking/failing IAC solenoid. Your 'normal' idle should be in the 800rpm range.

[Wicked_Sludge]

most O2's are due for replacing at about 60,000 miles. your '00 will trip a CEL if a sensor is far enough out of wack to cause driveability concerns.

id check for vacuum leaks first, clean my IAC solenoid second.

[HAPPY_RANGER_GUY]

Yeah, don't be too quick on the O2 sensor...probably the most often changed part for no good reason. Hell, I have 140K on my original sensors and truck does fine. Look elsewhere like Sludge said, or atleast test the sensor.

T.