Check Engine Light

My check engine light came on the other day, i plugged it in and the diagnosis was a heater o2 sensor i know i have an o2 sensor on my exhaust, but is there another sensor, or should i just go ahead and replace this, my truck runs fine, just a little rich since that light came on

 

There are 2 oxygen sensors on these trucks.

The oxygen sensors ARE heaters.....in a sense.

What code did you get? In most cases, the Bank 1 Sensor 1 goes bad. That's the sensor closest to the engine.

You can replace this yourself. If you have the 3.4L and you can diagnose that your front sensor is bad - here's a writeup on how to change it on a manual transmission.
http://www.lieblweb.com/o2replacement.html

 

Its most likey the Front sensor. Bc that sensor is the AFR sensor.
I had mine go bad and I was running rich, for awhile.
Rockauto.com has some good prices on o2 sensor's. Get Denso's.

Oh.. And It is alway's recomended to change both sensor's at the same time.

 

The readout on the check engine was P0141, O2 Heater Circuit, Bank 1 Sensor 2

 

Yep, thats the front sensor. But like I said, I would be safe and get both sensors replaced.

 

ya that the rear sensor the front is bank 1 sensor 1 this one is bank 1 sensor 2, this sensor is after the cat

 

Yeah, my bad! your right....

 

Agreed. It took me about 30 minutes to get the old oxygen sensor (bank 1 sensor 1) off and the new one on (02' Tacoma TRD Pre-Runner). This is an easy do-it-yourself fix that just about anyone can do. I did however decide to take it to the dealership for the diagnostic just to make sure I replaced the correct sensor. I think the error code came up as P1135.