Car running really rich, no codes

[bowsercake]

My car is completely stock by the way. Anyways, I reset my ecu when I was installing some battry terminal covers. After that I drove around and got 6 mpg, including some highway.

I reset the ecu again and I'm getting 10mpg. Usually I get 13-14 mpg all city. I checked for codes and I get no codes. I drove about 60 miles after reseting the ecu yesterday, is that enough time for it to get back to normal? If not, why else could I be running rich?

Also, I checked my Oxygen sensor and cleaned it out. I don't think that really changed anything.

Also, this just happened all of a sudden one day, it did not get worse and worse over time.

 

[CRE]

My car is completely stock

There's problem #1

I reset the ecu

And there's problem #2. That's most likely why you're running rich now... the ECU needs to relearn it's maps.


BTW, cleaning your O2 sensor won't fix it if it's bad.

 

[Nick M]

The problem is your lead foot, and quit unplugging the EFI fuse. Unplug it after repairs are made and a code was stored.

 

[stratoayu]

anytime u reset the ecu ur asking for bad gas mileage. it has to relearn.. usually it takes a full tank of easy throttle gas to get it all right again,.

 

[Kai]

Check the timing also, base timing should be 10' BTDC, mine was running 8' and drinking petrol like mad.