[Request] How To Replace Rear Oxygen Sensor

[CrazyCreashunz]

Remove the oxygen sensor from the catalytic converter with an O2 sensor socket (available from pep-boys or auto zone), remove the protective plastic shield from the new sensor, install into the bung, tighten 1/2 turn past contact to seat the crush washer, run the new harness up through the body grommet (silicone spray helps the grommet slip into place and seal correctly), reconnect the harness under the seat, clear the codes, and drive away.

I have done this and I dunno if it is just me but I feel as if I am losing more fuel than before! I got the CEL on yesterday with the code to replace and I have cleared the code after install of new O2 sensor.... what should I check if anything, I don't wanna over tighten the new O2 sensor and it seems to be in tight! Maybe it's all in my head I will see when I drive the car tomorrow where the gas level is at to when I get back and then I will know.

If code is cleared/new part installed and problem still exist due to whatever how long will it take until the code comes back if it decides to come back?

OKay I am not losing my mind I am losing too much gas. I checked to make sure plug was secure under the seat by unplugging it and replugging it. I dunno what else to do. Could it be the O2 sensor is not fully tightend that I may have a leak... Wouldn't that throw a CEL?

[timot_one]

Try resetting your ECU by disconnecting both battery terminals, wait like 5 minutes, then reconnect the terminals, and follow the idle learn procedure.

[CrazyCreashunz]

Try resetting your ECU by disconnecting both battery terminals, wait like 5 minutes, then reconnect the terminals, and follow the idle learn procedure.

Will do Tim, what is the idle learn procedure... just drive around like normal so the ECU can relearn my driving habits. Sorry for the noob ? I not on the computer to search... I will look in the manual since it is right here with me!

[Skippy]

Disconnect the battery for 10 minutes, reconnect, then start the vehicle.  Leave it running with all electrical loads off for 10 minutes. That completes the idle learn procedure.  The O2 sensor should be tightened approximately 1/2 turn past finger tight with an O2 sensor socket.  If you are having problems, you will throw codes.  If you are not having problems, you will not throw codes.  O2 sensor codes come back almost instantly if there is still a problem.  You cannot run the car for any longer than about 10 seconds with an existing O2 sensor fault.  If you cleared the codes with a bad sensor, then turned the car on, the codes would come back instantly.

Poor fuel economy can be due to a couple of reasons, most likely bad gas or the amount of ethanol they're introducing into the mix.  Our cars weren't designed to burn it, and contrary to big brother's plans, it does nothing but make fuel economy worse and reduce corn supplies for human consumption.

[CrazyCreashunz]

Disconnect the battery for 10 minutes, reconnect, then start the vehicle.  Leave it running with all electrical loads off for 10 minutes. That completes the idle learn procedure.  The O2 sensor should be tightened approximately 1/2 turn past finger tight with an O2 sensor socket.  If you are having problems, you will throw codes.  If you are not having problems, you will not throw codes.  O2 sensor codes come back almost instantly if there is still a problem.  You cannot run the car for any longer than about 10 seconds with an existing O2 sensor fault.  If you cleared the codes with a bad sensor, then turned the car on, the codes would come back instantly.

Poor fuel economy can be due to a couple of reasons, most likely bad gas or the amount of ethanol they're introducing into the mix.  Our cars weren't designed to burn it, and contrary to big brother's plans, it does nothing but make fuel economy worse and reduce corn supplies for human consumption.

Done... disconnected the power and negative for 10 minutes now I will run car without any electrics on. We will see if this helps, I hope so cuz I never had too much gas burning like this before the damn O2 sensor went!

Thanks for all the help guys... will report later if im still burning a lot of gas.

[CrazyCreashunz]

Well I did all the above, disconnected battery terminals for 10 min. to reset ecu then turned car on with any electric on for 10 minutes, checked the plug under the seat disconnected it and reconnected it again tightly. I know for a fact that the O2 sensor is in cuz my popz tightened it after making sure I did it right... and I still feel like im burning too much fuel. Maybe I got bad gas like Skippy said, I guess I will have to burn through it and refill again at another gas station. I never had this problem before the O2 sensor went out on me.

If I refill an empty tank with new gas from another gas station and I am still burning gas too much what should I do, take it to the dealer?

[Skippy]

So...how much mileage do you think you're missing out on? Just have to ask.

The reason I ask is because there's virtually no mechanical reason for you to be burning more fuel than usual.  If you had an injector stuck open, you'd throw codes.  If you had REALLY bad fuel, you'd throw codes.  If you had an emissions problem (which results in bad fuel economy), you'd throw codes.  

If you're not throwing codes...there is a very small chance of a mechanical issue.  Try to think about stuff that might contribute to your poor fuel economy such as increased city driving, increased weight in the vehicle, increased use of air conditioning, a change in gas stations OR fuel grades (93-89, 89-87), or something along those lines.  There's no test you can perform on your gasoline to see if it's good or not, and frankly who the hell knows what any of us are putting into our fuel tanks these days.  You can get bad gas from any station at any given time.  Here's a test for you.  For the next three tanks of fuel, I want you to log your fuel mileage along with the type of driving done during that tank.  I also want you to go to the same gas station, gas pump, and get the same fuel every time.  Post your results here.  If those three tanks get bad results, switch gas stations and do it all over again.  If those three tanks suck, then take it to honda.  Honda will tell you to do the same thing that I've just outlined, so save yourself and the technicians the time and do it now to see if we're actually talking about a mechanical issue.

Since I have a TSX tranny, my numbers are going to be off, but just to give you an idea, I usually get about 350-360 miles per tank on 87 grade fuel.  That's a little over half highway, half city.

[InFuMoUs]

Maybe you can add a bottle of techron. That has helped me before, but I had that same problem when my O2 went bad Billy. You should be fine on the next couple of fill ups.

[Skippy]

Adding transmission fluid to your fuel is not a good idea...that's an old school trick and it would probably not work well with K series engines...

[CrazyCreashunz]

Maybe you can add a bottle of techron. That has helped me before, but I had that same problem when my O2 went bad Billy. You should be fine on the next couple of fill ups.

Adding transmission fluid to your fuel is not a good idea...that's an old school trick and it would probably not work well with K series engines...

Yea that is an old school trick... I think im back to normal now. Took a nice trip to FDR State Park yesterday and wasted only a quarter of a tank, exactly what I should of! I think the ECU just had to get use to the new O2 sensor that's all. Glda this is all cured for my my trip to the Sunken Meadow meet...

THANKS FOR ALL THE HELP GUYS!  :grin:  

[InFuMoUs]

What old school trick? I thought Chevon Techron was a gas treatment. I never said anything about adding transmission fluid, but glad ya ride is back to normal Billy.

[Skippy]

Ah I must have been thinking of Dextron-Murcon (an old branding of transmission fluid replaced by Chevron fluids).  

Transmission fluid has been used for a long time to clean out fuel systems.  You would add a bit to your fuel supply and it was thought to clean out the system...personally I think it would not work well in K motors.

[InFuMoUs]

Oh ok. That's the first time I every heard of people doing that. The one that I know of is people adding transmission fluid into the oil and letting it run to supposedly clean the engine before doing an oil change.