I just changed my o2 sensor seeing that the one that was in it was burnt (it's the upper o2 sensor by the way) and the check light was on. Upon changing it, the light went off right away, however, now I seem to be spending alot more money on gas than when the o2 sensor was busted. Can someone tell me why this has occured? (gas is like $4.680 right now over here). Thanks in advance for your help.

 

what brand did you use and how much. need to chang mine also. dont know why the bad mileage. maybe you should chang the downstream also might be getting a bad reading between old and new.

 

If memory serves me correctly it was Denso Honda OEM 36531-P0A-A01. Came in the Honda package and everything so I know it's genuine. Maybe I would need to fill my tank and treat the gas. I did that the week before changing the sensor.....who knows, maybe it'll work huh?!

And if you mean what brand gas, it was esso unleaded. Sometimes I go to texaco but that depends on the pricing of gas at the time. I do however try to avoid mixing gas as much as I could.

 

did you unplug the battery while changing the o2 sensor?

if you didn't, disconnect the negative terminal of the battery for about 15 minutes, reconnect and then drive around for a while so the ECu can relearn its sensor settings

 

did you used the scanner to determine it was a bad sensor...WOW my o2 sensor also went out on my 00 Si. I didn't buy it from the dealer it was almost $350 yeah right [:@]...I went to a local foreign auto parts I bought a DENSO o2 sensor for about $150. Mine came in a Denso package. The dealer parts are also Denso the only difference is that there parts come in a Honda package but the part is Denso and that's what matters. Next time I suggest to look somehwere else if the part you are trying replace it says DENSO. You will save some $$$$$$.
ABOUT WASTING more gas it's weird...Is the Cel light ON.

 

I don't recall unplugging the battery at the time so I will do just what you recommendedbright and early tomorrow morning. Thanks cderalow.

To Civic Si 00: No, I actually didn't use the scanner. The check light was on and I looked up the code in the service manual. That and to be sure, I asked a few mechanics....I didn't bother buying a new one but this one was fairly new (inspected it throughly) for about $35. Took me a few months to find a deal like that. Surely enough though when I took out the old sensor it had a burnt to a crisp look. And no, the CEL light isn't on, just my srs seeing that I had my airbags changed due to an accident a few months back, haven't looked into that one yet (lights annoy me that DON'T have to be there).

 

Unplugged the battery as suggested but for more than an hour to be sure. Still takes a good amount of gas. Maybe fill the tank and treat the gas again seeing as it was done BEFORE changing the sensor?