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Is it mandantory to reset ECU after replacing UPsteam O2 sensor?

DaveNC

Be Gentle I'm New Here
Joined
Oct 15, 2003
Messages
3
Had to replace my up stream 02 sensor on bank 1 this weekend and I didn't bother to reset the ECU. My gas mileage starting going bad again just like last year around this time and last year it was bank 2 (front). When the front went bad without a code my front spark plugs got ate up apparently because of a rich condition. I guess I should have just replaced both upstream 02 sensors at the same time. The rear one is a pain in the ass to replace BTW.

So is it a must to reset the ECU after replacing an 02 sensor?
 
you don't have to but it is a good idea. it lets the pcm start fresh and not have to relearn itself.

don't forget that fuel milage will drop this time of year because of the cold, etc ...
 
you don't have to but it is a good idea. it lets the pcm start fresh and not have to relearn itself.

don't forget that fuel milage will drop this time of year because of the cold, etc ...

I normally get between 390 to 400 miles before the light comes on. I can then run another 30 to 40 miles before I fill up. I started getting 360 which is the same thing that happened last year and my front bank sensor went out.

My mileage is back this week after I changed the sensor out this weekend. I also got the 0420 code a few days later. I just finished putting in some seafoam this evening through the vacuum on the intake and then I put a whole can in a full tank of gas which I'll do again on the next fill up. I normally get between 29 and 29.75 mpg on a consistent basis (year round in NC)so when I start getting less I know something is wrong.

This forum has saved me some money numerous.

Thanks,
Dave
 
.... I also got the 0420 code a few days later. I just finished putting in some seafoam this evening through the vacuum on the intake and then I put a whole can in a full tank of gas which I'll do again on the next fill up. I normally get between 29 and 29.75 mpg on a consistent basis (year round in NC)so when I start getting less I know something is wrong.
...
If the P0420 stays, it may be time for mileliminators.
http://www.contour.org/ceg-vb/showthread.php?t=760
 
Accrding to the Ford OBDII guide the DPFE sensor is monitored once per driving cycle, it take 4 seconds to register a malfunction
 
mils are only for down stream sensors, or the cat monitoring sensors, and you still need to have working sensors also ...

so no they will not work on sensor 1

That is what I thought. I am still used to my 95. :laugh: Why oh why couldn't they just go back to that.
 
Well the 0420 didn't come back so it looks like the seamfoam worked. I was getting the 0420 about every 10 minutes and now it's gone.

Thanks again
 
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