I am pretty sure that my oxygen sensor is faulty. I have a EF civic sedan with a b20. I am throwing a code 43 (obd1) which is fuel system malfunction and I am getting attrocious gas mileage. I have a soare sensor at my sisters house but I wont be heading there until thanksgiving.

So, I am assuming that the car is running in closed loop. Does this mean that the sensor is not functioning at all or is the sensor just not reading the right values. It is obvisously not reading that I have unburnt vapors. I dont have a cat right now so I'm not worried about messing anything up; I just dont want to fill up every 200 miles.

Is there a way that I can lean out a bit? Would a higher octane fuel be benefficial? Should I be driving around at a higher RPM range? Also, could this be something else not associated with the 02 sensor? The car is a obd0-1 swap, so it has bugs...

Thanks for the help and insite, (assuming I get some)

-Justin

 

The really obvious anwser to your question is get an o2 sensor. Closed loop is getting feedback from the o2 sensor, open loop relies strickly on the fuel maps. Higher octane is only benificial for higher compression, and turbo's, or if you really advanced your ignition timing alot.

 

Is this a stock ECU/motor?

Check things like your fuel filter, cap, rotor, return line...etc. but most likely you just need a new o2

 

Yea, It is the stock engine and ecu. I bought the car with very hacked wiring. I've been going through the whole car and re-doing everything but there are still bugs that may be wiring related.

I have a couple extra 02 sensors at home. I am in school as a full-time student and wont be home until thanksgiving. I do alot of driving and just wanted to know if there was something simple I could do to temperarily replenish my gas mileage a bit.

I will replace the cap and rotor on thanksgiving break as well and most likely replace the fuel filter. Thanks

 

Without chipping the ECU, if your computer thinks your "Fuel System" or more likely your O2 is defunct, it is going to keep dumping a ton of fuel.

 

 

Ok. You answered my question. I thought that the faulty 02 sensor was just sending incorrect signals to the ECU. I undersand now. Thanks