so what gives... im on my first tank of gas after changing my original 02 sensor for a new bosch one.

Is the mileage going to climb back up?

cheers

 

I am suprised you went with Bosch, there is a real consensus that you should only use NGK or Denso O2 sensors, plugs, etc on this board. Wither way, it could be a fluke. I had a bad mileage tank after relacing my TPS, then it went back to normal.

 

I hate to say it, but people have had really mixed results with Bosch O2 sensors. It seems that some of them are a little shorter than factory, so they don't stick into the exhaust stream enough to heat up and work properly. A better bet is an ND or NGK (original equipment but loads cheaper than from the dealer) from http://www.sparkplugs.com/. Probably not what you wanted to hear, but that's been my experience. If you can, I'd try to return the Bosch and get an ND or NGK.

 

WOW those are cheap! I paid 136.00 from the dealer 5 years agoGotta add that one to my favorites

 

hill,

been here long enough and read threads similar to yours enough to know that its your choice of 02 sensor. go stock toyota OEM.

bob

 

Yeup... there're gajillions (well, maybe just under a gajillion) threads here stating OEM ONLY!

 

I thought I might share my bad experience with the Bosch 13104 O2 sensor...

After reading the 4x4wire tech article we decided to replace the original (106K miles) front O2 sensor on my mom's '98 3.4L 4runner.

I wanted to get the OEM sensor from the dealer, but they were closed for the rest of the weekend, and I was leaving town on Monday. Without thinking, I bought the Bosch 13104 from the local parts store since they had it in stock, and the special-order Denso would arrive too late.

I noticed right off the bat that the sensor head was much shorter with a thicker flange. This should've set warning bells off in my head but I installed it anyways. After resetting the ECM and driving it around for 10 minutes all was fine.

Later on that night the CEL came on. I assumed this was normal as the same thing was documented in the above article. A quick reset of the ECM and it's gone, 'till it came back again the next day. We went back to the parts store, had them plug in the scanner, and pulled code PO125, just like I thought. I went home, reset the ECM, searched forums like this one, and realized that I'd pissed away $124+tax :pat:

Based on the conditions required to trip code PO125, the POS Bosch sensor probably sat too far out of the exhaust stream to warmup quickly. We didn't drive much, but it looked like we burnt thru 1/4 tank of gas much faster than normal (my mom doens't reset the trip meter at fillups so I had no idea on the mileage).

After a lot of haggling we got very lucky and exchanged our *used* Bosch 13104 for the correct Denso 234-4162, which will arrive in a few days.

In the meantime we're back on the original 8yr old O2 sensor with no CELs.

CN: Friends don't let friends buy Bosch O2 sensors for their Toyotas...

 

So would the Denso be worth 30 bucks more on that site compared to the NGK that says it's also OE identical?

 

I wouldn't know. I just bought the Denso at the local parts store since I could only get store credit for the Bosch, and it seems as though most people recommend that or NGK (which wasn't available at this particular store).

 

ngk makes really good stuff cant go wrong with there o2 sensor

 

Lots of parts come from the dealer with DENSO on them, so I can't see what difference it makes if its Denso or NGK

 

where are the prices for o2 sensors on that site?

 

Denso is considered OEM for Toyota, NGK is not.


Once you drill down to your vehicle, there's a drop list on the upper left for "product search". Click it, and pick "O2 Sensors".

Don't forget URD for O2 sensors. Guaranteed real OEM, not "OEM replacement":

http://www.urdusa.com/product_info.p...s_id=430006000

 

Thought I might share, installed the Denso sensor and no probs

 

...which would be expected since Denso is OEM.

 

It still works the same, but compared to a new off the shelf OEM Toyota sensor (got to look at one at the dealer), there is some difference in shape.

While the flange and exterior body design is pretty much identical to to the Toyota part, the sensor head is not. The OD is *slightly* smaller, the length of the head is the same, but the actual shaft is different. It's hard to explain, but the lower half of the sensor shaft is just a solid shaft, while the upper part has the holes and dark brown/burnt color. This was a Denso 234-4162, installed before the cat on a '98 3.4L 2wd Auto.

 

On a related note, I installed a new Denso O2 sensor with my LCE headers (22re) and have been getting lower mileage and a CEL. Haven't run the codes yet, but will it be a problem that the O2 sensor is now all the way down by the cat instead of on manifold like stock?

 

On my truck there's an O2 sensor right in front of the cat. Haven't taken the heatshield off of the headers, but I don't think I've ever seen one down there.