O2 sensor, front or rear?

I had the dude at the parts store run a test for my check engine light but could only tell me it was "probably an O2 sensor"

Is it worth going to the dealer or mechanic to get the right code that lets you know which sensor is out?

Are the diagnostic readers they sell at parts stores any good and are they worth the investment?

With help from this site I already know I can do the job myself (thanks!) but need to know which one, or both.

 

I see you have a 2004 .
A good quality scanner will be able to identify the proper O2 sensor .
With this said you are OBD2 compliant so a scanguage or an ultraguage would do the trick
http://www.ultra-gauge.com/ultragauge/
http://www.scangauge.com/

 

These things read codes too? I may invest in one.

 

They sure do, my Ultragauge went off on me when I was carrying a bed full of dirt one time. I was climbing up a huge hill and the truck got a misfire code. Turns out a spark plug wire had come off and the Ultragauge helped me out by letting me know right then and there. Also a four cyl Tacoma is slow already, imagine one full of dirt and only running on three cyls lol.

 

They sure do

 

Interesting, Ultragauge is 69.95 and the other is $100 more. If the cheaper one will do what I need it to (give me specific info on check engine light) than it's a no brainer

 

Wouldn't a cheap bluetooth reader (usually < $10) with the Torque phone app ($5) work? I know it reads everything, including codes, on a newer BMW so it seems like after you put in the Tacoma specs it would work. Makes for awesome custom dash panels.

Not sure if it is available for Apple.

 

I bought a ScanGauge II a few years back and have used it in every vehicle I have. I got the check engine light, utilized the SG2 by pulling the code (P1135), did some research and it ended up being the sensor. I bought the before-cat a/f sensor (

$149 Denso 234-9001 Upstream Air Fuel Ratio Oxygen Sensor with 10.6” 4-Wire Harness, for Auto Trans Equipped Vehicles

Denso 234-9001 Air Fuel Ratio Sensor) and after-cat O2 sensor (

$70 Denso 234-4189 Oxygen Sensor

Denso 234-4189 Oxygen sensor). Installed the a/f sensor, check engine light went away. I have heard the O2 sensor can throw a CEL shortly after, so I bought it as a precaution. Hope that helps!

 

Wow! This seems like the answer and under 20 bucks! I'll have to check this out, thanks

 

One thing to keep in mind, is the scan/ultra gauges work in real time, and have their own screen.
They will both tell you immediately if the OBD2 throws a code, but does not light the check engine light.

 

yes but you still need to go to scangauge menu and hit scan to reveal pending codes

nothing on scangauge will 'pop up' and show a code unless you ask it

but yes scangauge is baller

 

Does anyone like the ultra gauge over the scan guage?

 

Ah
The ultra gauge will pop up and tell you that there is a code. And sound an alarm on the unit. Very useful for telling me when i don't tighten the gas cap all the way.

 

I'm heavily leaning towards the ultra gauge since I heard it can read auto trans temps.

 

hmmm....scangauge can read both trans temps... hot side and cold side

quite easily

 

It sounds like I was misinformed on that.

 

Ok so I got a Bluetooth OBD2 adapter and downloaded EngineLink app

Got the PO136 code. So which damn sensor is it?!?!? Front or rear O2 sensor?

Getting pissed off that this particular gizmo I got doesn't tell you which one, which is the whole point of getting the frickin thing

 

AAAAAAAND now the ABS light is blinking too

 

a 30 second internet search http://www.obd-codes.com/p0136

 

Bank one sensor 2 is the sensor after the cat, yes?