help! could it be oxygen sensor?

[atblacktalon92]

My gas millage averages around 18-20mpg . I checked my oxygen sensor output voltage, but im kinda confused which pins to check because, the haynes manual shows the oxygen sensor pinouts seem to be the other way around when I probed the pins and get the out put voltage. My out put voltage readings from the sensor side shows from 0-.1 volts at idle but when i tried increasing the rpm, the reading still stayed from from 0-.1 volts. The resistance reads 12 ohms. Is there a better way to check the oxygen sensor? Im still confused if i did checked it properly becuase of the pinouts seems to be the other way around when i get the readings.

 

[Turblown]

I know this thread is beyond dead and kinda confusing, but does anyone have any info on the accuracy of the Hayne's Manual with respect to the Oxygen sensor check? I'm having similar issues.

Here are some follow up posts to look at:
Tech Article
Another Thread

 

[luv2rallye]

Both Haynes and Chiltons are terrible and often wrong because they group many years and models under the same component/testing descriptions which often is not true. Other things are just plain wrong - like torque specs. Some things they don't cover at all - but then they are the cheapest manuals so you get what you pay for. The factory oem manuals are the best, always accurate, pricey but worth the money in my opinion.

Here's my take on service manuals (from best to worse):

1) Factory Mitsubishi Eclipse Service Manual is by far the best, ALWAYS TOTALLY COMPLETE AND ACCURATE, but pricey (>$100 new dealer hardcopy (http://www.diyrepairmanuals.com/), try eBay for cheaper used one).

Aftermarket service manuals:

2) Alldata (http://www.alldatadiy.com/) - excellent, has every year descriptions, this is the professional one used by the automotive service industry, by subscription only (around $27/car/year), avail free at some libraries to look at or copy pages.

3) Shopkey (http://www.shopkey5.com/) - Snapon's professional one by subscription only, similar to Alldata but VERY pricey.

4) DSM Backup Manual CD - Copies of: Factory Service Manual (FSM) years 91,93,96,97; factory 1g and 2g Technical Manuals; 89-93 Galant Service Manual; DSM Transmission Overhaul; VFAQ; 1000 already answered questions. These are copies of the real FSM's. However, some lines/letters on some pages are blurry, faded, or doubled on top of themselves. Order CD at Forced Performance Turbochargers: Service Manual CD.

(or get free ones to download at https://web.archive.org/web/20121107121312/http://timramich.com/dsmbooks/ - note some of the manuals links don't work anymore)

5) Mitchells - good, has every year descriptions, avail free at some libraries to look at or copy pages. You can rent a Mitchells manual online for a week, month, or year at Free Auto Repair Manuals | Online Car Repair Manuals. Also at http://www.ondemand5.com/

6) Chiltons - cheapest, available in auto stores, often incomplete or inaccurate for your model/year due to many models/years being grouped together under one item's repair/test/picture description, some things not covered at all or poorly - but better than nothing.

7) Haynes - same as Chiltons: cheapest, available in auto stores, often incomplete or inaccurate for your model/year due to many models/years being grouped together under one item's repair/test/picture description, some things not covered at all or poorly - but better than nothing.

And for this threads subject, here's some info on O2 sensor operation/testing: O2 Sensor FAQ

And here's a link to all Mitsubishi cars manuals: https://www.mediafire.com/folder/5k14qlaulb9s1/dsm_mitsubishi

 

[viprez586]

Cleaning your O2 sensor is simple, use isopropyl alcohol to clean all the carbon off of them.
O2 sensors rarely go bad.

 

[projekt1]

O2 sensors rarely go bad.

Anybody agree with this statement? Is it true? The reason I ask is because I'm looking into buying a replacement but if I can safe money by just cleaning it I will.

 

[projekt1]

Wisemen??

 

[Avionixx]

Oxygen sensors are not considered wear items, so I would agree with that statement; assuming you're not burning oil, running leaded gas, or running on three cylinders or less on a daily basis.

The best way to check an O2 sensor is with an oscilloscope or some kind of graphing multimeter hooked up directly to the signal wires. This way you can check anything from the switching voltage range, time it takes to switch from lean to rich, and the time it takes to react to a sudden change in mixture (vacuum leak or propane through the intake).