[srbianats]

Originally Posted by jozuah

04 TB LT all option packages, Running boards removed (it was that or buy a suit and i "aint" buyin' no suit) has 53K miles and i use 89 octane 10% Ethanol fuel in Iowa.
I have changed the 02 sensor on the E/manifold due to a code and was wondering about changing the other if i have noticed a fuel economy change ,, i get 13.8 in town stop and go driving no more than 50 MPH for any length of time. and i get 17 - 18 Avg. MPG on the interstate ( semi-hilly 75-80 MPH). Last note for anyone who may wonder, the S.E.S. light flickers for an instant about 5 -7 miles after i start the truck for the first time during the day,no hard codes (im thinking it's at that point it switches from closed to open loop)..
should i replace the downstream one ?
TIA
Joz

When was the last time you checked your plugs and wires? SES light flickering could be misfires. A plug could be going or wire has a crack.