O2 sensor hack or something? HELP!!!

[mpg_numbers_guy]

Ok so apparently the O2 sensor on my car WAS bad. Torque showed my FE for this tank at 48 MPG with several 60-61 MPG trips. HOWEVER I filled up yesterday for only 40.5 MPG! LOWER than the 42.5 I got BEFORE Torque and half of my current ecomods!

Apparently my O2 sensor is screwed up, and it's the more es pensive $200 one. Yes I'm mad lol.

So....how do I clean it? And is there a way to hack the system or something to bypass the sensor and still make it run normal or even lean as far as fuel economy goes? I honestly don't care about emissions since I drive efficiently enough to make increased emissions not an issue.

Would an HX lean burn sensor work since that's not much more than the traditional one? Or am I looking in the wrong place and are they not really that expensive?? I am SO mad lol. I could literally freaking DRAG RACE and get 40.5 MPG.

Help, advice, and tips appreciated! Anything but spending $200 on the new part!!!

[Stubby79]

Wide-band?

If not, a generic one with the right # of wires should work and cost a heck of a lot less.

[California98Civic]

Don't throw parts at the problem until you have properly tested and know what the issue is. You could waste money and time and get angrier. Your FE drop could be caused by a few things, including a vacuum leak or a bad MAP sensor. How do you know it is the O2? You have a code? (Btw, you can't use the wide band in a non-leanburn Civic).

EDIT 1: I thought you had an LX, but you have the EX. It might use a wide band. Not sure.

EDIT 2: Also, does a Torque app need calibration? Part of your problem could be the app is not calibrated properly and is misinforming you so that you get quite a surprise when you get to the pump. Calibration might help.

[Xist]

Honda Parts Now charges over three hundred for each oxygen sensor. They have competitive prices on OEM parts. Rock Auto has NTK sensors for $162. I have never found a better price than Rock Auto.

It frustrates me when I put 2004 Honda Civic EX O2 sensor, I get results, and each page asks what make, model, submodel, and part I want.

I told Google and you said you had it!

I happened to see Air-fuel sensors. My Civic may need one. Those are expensive, too!

Of course, she also has low compression, a bad head gasket, and overheated driving five miles downhill.

Please do troubleshoot! Good luck!

[oil pan 4]

The O2 sensor is a consumable item. Plan on replacing them every 70k to 100k miles for best fuel mileage.
If you buy a universal O2 sensor you can just about cut the price in half but you have cut off and reuse the vehicle sensor plug.

[mpg_numbers_guy]

Originally Posted by Stubby79

Wide-band?

If not, a generic one with the right # of wires should work and cost a heck of a lot less.

P0135 error code.

Originally Posted by California98Civic

Don't throw parts at the problem until you have properly tested and know what the issue is. You could waste money and time and get angrier. Your FE drop could be caused by a few things, including a vacuum leak or a bad MAP sensor. How do you know it is the O2? You have a code? (Btw, you can't use the wide band in a non-leanburn Civic).

EDIT 1: I thought you had an LX, but you have the EX. It might use a wide band. Not sure.

It's the P0135 code that it threw me at near the beginning of this tank.

Would the other things you mentioned, vacuum leak and bad MAP sensor, throw CEL codes?

Originally Posted by California98Civic

EDIT 2: Also, does a Torque app need calibration? Part of your problem could be the app is not calibrated properly and is misinforming you so that you get quite a surprise when you get to the pump. Calibration might help.

Torque never showed a dip in FE after the CEL came on for me.

I haven't bought the PRO version of the app yet, so I don't think there's a way to calibrate it. It was fairly accurate for the last quarter of my previous tank, within 1 mpg, when comparing it's output with my eyeball comparison on the fuel gauge (20 tick marks on the fuel gauge make it fairly accurate ) and the actual mileage.

But there's like literally no way this tank should've been lower. Previous tank was 42.5 with half the ecomods and no instrumentation for most of it. This tank had warmer weather, more ecomods (that tested for positive improvement), better routes, and P&G for the last half of it, with 5 trips over 60 MPG indicated. 48 is reasonable enough compared to my previous tank, and the only negative change I can think of is the O2 sensor light.

Originally Posted by Xist

Honda Parts Now charges over three hundred for each oxygen sensor. They have competitive prices on OEM parts. Rock Auto has NTK sensors for $162. I have never found a better price than Rock Auto.

My dad works at a Honda dealership so he can get me one for $200-$210 I think? And I thought that with Hondas going with off brand parts is just asking for them to fail sooner down the road?

Originally Posted by Xist

Please do troubleshoot! Good luck!

Ugh but thanks lol.

Originally Posted by oil pan 4

The O2 sensor is a consumable item. Plan on replacing them every 70k to 100k miles for best fuel mileage.

Should've asked about that when negotiating for the car back in January.

Originally Posted by oil pan 4

If you buy a universal O2 sensor you can just about cut the price in half but you have cut off and reuse the vehicle sensor plug.

How hard is that to do compared to just replacing the sensor with the "right" one?

[Stubby79]

O2 heater circuit? theoretically it shouldn't need it once the exhaust has warmed up.

Has the torque app been this far off before? If not, perhaps there was human error in the fueling process/math.

[oil pan 4]

Cutting off the old plug and splicing it to a new sensor uses about $1 worth of solderless connectors.

[Xist]

When I had an 02 error code "Heated" was part of the description. Doesn't the sensor heat itself as needed? I think that heating it is also part of the troubleshooting.

I am sure that there are good brands. I just know that for Hondas with lean burn, everybody who has tried non-standard oxygen sensors has ended up purchasing NGK\NTK, although often from a different source. I only bought Honda parts to replace my timing belt (and the rest of the belts, the hoses and seals, etc.). I think that the original water pump and hoses have 195,000 miles on them.

There are some situations where the manufacturers cannot get their act together, like Subaru and their head gaskets. When I replaced mine I bought Fel-Pro, but if you can get a good price for Honda parts, I cannot imagine using aftermarket ones.

[California98Civic]

You definitely need to test the circuit for that O2. That is a circuit code. It is probably the sensor. It could be an open in the circuit, even an intermittent one. Don't spend your money on an O2 without testing. Testing is easy. Though you may end up in the same place, you will know you are in that place, rather than having guessed. If it is an open in the circuit, the fix could be quite a lot cheaper. To me this is good eco practice too: not trashing and replacing perfectly good parts.