I just changed my front A/F Sensor (Cali Spec) and rear O2 sensor and my MPG dropped about 4mpg...what gives? Any ideas? Used OEM sensors, Tire Pressure is good, weather is getting colder but shouldn't effect MPG that much.


What do you guys think?

 

Disconnect the battery to let it reset.

 

I actually did that...and pulled the ECU fuse as well.

 

Huh, thats odd then-I dunno

 

you might have tightned it too much or damaged it when you were installing it

 

man thats wierd, i just changed mine, and my milege jumped, there are no cel on are there? if so you mite put it on obd2 and see what it reads

 

anit that backwards ? thought the front was a o2 sensor or is it different for cali spec ?

 

Cali Spec has an A/F and O2 back. I had a CEL before thats why I changed the sensors out. I unpulgged the battery to reset the CEL, and been running really smooth ever since...but getting 14.xx MPG.

 

Where did the sensors come from? Are they OEM?

If you still had the old ones you could try swapping back one at a time and see if it is actually the sensors or just maybe that they switched to winter gas during your swap.