ngthing

I couldn't find anything usuing the search function, does anybody have info on testing the O2 sensor?

kaleb

Well the resistance should be 2.3 - 4.3 Ohms depending on the richness of the exhaust.

You'll have to test it when it's hot and when the engine is running. Pretty scarey stuff to lay under the car and try that...

eric93SE

iTrader: (1)

If you need exact directions e-mail me.
I actually just replaced mine this week. The diagnostic mode said it was good, but over time it''ll affect gas mileage.

I have the ve30de engine, but i think the diagnostic procedure is the same.

you need to uncover the ecm on the right side of the center consol. removing the two screws holding the trim piece in place. then get the engine up to operating temps. there is a small flat head screw on the ecm (it may be covered by a clear sticker, peal it back) this screw is how to get the ecm in diagnostic modes one and two. by turning the screw and waiting three seconds then turning it back gets you into the first diagnostic mode.

I''m not sure which mode for the oxygen sensor test but you can just try both.

the ignition must be on but engine not running
one mode reads out any fault codes ( by counting the number of flashes from the check engine light or the led on the ecm), and then the other mode tests the performance of the 02 sensor.
to test the 02 sensor you must have the engine running (and like I already said warmed up) and while you are in the diagnostic mode (one or two) race the engines rpm at 2000 then the ecm will start to read out on the check engine light. The number of flashes should be between five and ten within a ten second period. If its more or less or nothing, well you know

so to get to diagnostic mode two, you should turn the screw wait, turn it back wait, turn it again then wait, and then turn it back.

if you turn off the ignition the ecm returns to its orignal setting.

crsmax

What is the difference between the OEM O2 sensor and the "racing" O2 sensors that have five wire attached instead of three like OEM? Do they even make the five wire O2's for our generation max?

NYC GS4

iTrader: (2)

Since you say your getting 16 MPG, I'd say it most likely is a bad sensor. Since it very well could be your original sensor, just like it was for me.

Simply get under the car and unplug it. (The sensor plugs in on the right of your front exhaust pipe, you'd be looking for the electrical connection coming out around where the rear engine mount is, just trace it with your fingers if you cant find it). Then drive around like that, if you see hardly any difference in MPG/driving conditions, then go right ahead and change it. Just make sure the car hasnt been touched for at least 3 hours or so, cause the sensor tends to get very hot.

Just an example, I just finished off an entire tank of gas with no 02 sensor at all. I got around 16.5 mpg, the only thing is my car was fully tuned up this summer. Judging by everything, the sensor is your problem. Change your PCV valve and Fuel Filter while your at it( Under $15 for both, very easy install)