YM13

In reference to the title, I ask this question because about a year ago my check engine light came on and the dealership told me my 02 sensor needed to be replaced. So about a year afterwards I bought both, and had a shop deal with the rusted bolts and put them in. However, I have not noticed a real change in gas mileage since then and I have replaced spark plugs, cleaned MAF and cleaned the air filter (K&N). Gas mileage is not only undesirable but it is a lot less than what it used to be. So I am wondering what if the garage swapped the two sensors? Would this throw a code or would the vehicle keep going with some sort of false readings contributing to poor gas mileage. If so, how do I find out or check? is there a number on the actual 02 sensors themselves?

Thanks in advance!

YM13

Anyone have any thoughts?

TheDurk

As long as the plugs fit and the wires reach, on a '97 it would make NO difference whatsoever. Look here: http://www.densoaftermarket.com/cata....php?part=o2sn

The same universal is used front and back 234-4206 on all models. The only differences among the application specific sensors are wire length and possibly plug configuration--but I suspect the plugs are indeed the same.

Whole different deal on a '01-'02 or a '99-'00 Cali. The front and rear sensors are TOTALLY different. Aside from the plugs not fitting, I'm sure the ECM would freak out. Not to mention the '01 and '02 have one screw-in and one flange type.

YM13

I ordered the 4161 and the 4154 from amazon...with those two different O2 sensors will there be any difference?

waskillywabbit

iTrader: (-1)

If something was wrong with your O2 sensor(s) your CEL would have told you right away.

:wabbit2:

YM13

Alrighty thanks for the help...I guess I'll have to scour the "why is my gas mileage bad" posts to find some answers on what may be happening...

yotaman85

what is you MPG?

TheDurk

4161 is 15.35 in long. 4154 is 12.91 in long. The plug looks to be perfectly identical. The sensor itself IS identical. The only difference is wire length. If you try and put the 4154 in the upstream hole, the wire might not reach, but if it does, it will work exactly the same as the 4161. On the downstream hole, the 4161 will have too long a wire, but will function perfectly.

YM13

Awesome thanks for that information!

YM13

I get around 13 maybe 14 around the city and that is babying the pedal cruising around..I used to get 17 or so...