Hi Guys... I am getting really poor mileage (City/Hwy around 14-16 mpg on 93 Octane).. My 08 Journey 5AT just hit 121K mi and I have done everything except change the AF Ratio Sensors.

Voltage range measured by Torque for both Bank 1 and Bank 2 upstream are between 1.9V ~ 2.1V. My Short term fuel trims are as follows -

Bank 1 -8% to -12%
Bank 2 -15% to -20%

I fixed a crack on the exhaust system and reset the Fuel trims this past weekend so I am yet to get fresh numbers off of Torque.

My question is, should I change my A/F Ratio sensors? At 120K, they are probably at their end of life.

Also, I see many comments referring to getting the OEM upstream sensors Vs OEM Types (like Denso, NTK etc.). How many of you have tried OEM type Denso/Bosch/NTK and didn't trigger any codes after?

I don't have any A/F codes yet but wanted to be proactive to fix my crappy MPG issue by replacing them before they started throwing a code.

Also, I have replaced spark plugs, PCV valves, MAF sensors. I have K&N Air filters.

Thanks in advance.

 

BTW, I already ran Seafoam through the fuel tank and the crankcase per instructions. I am not sure if I need to do a fuel injector flush.

 

Have you done all of the resets (ECU, Throttle Body, idle speed reset, etc)?

 

Could be your driving style or perhaps you should try regular 87 Octane
On road trips from NJ to Florida I get excellent MPG
Short trips while in Florida not so much



I usually obtain my regular here



or here when on the road



All regular all the time



Telcoman

 

Yes. I have been doing all the resets. I am literally at the end of the road here except for replacing the AF sensors and/or doing a vacuum leak test.

 

That is some good MPGs.

 

Prior to replacing parts there is only one accurate way to measure true MPG
Fill tank, drive 300-350 miles on an interstate at a steady 70-75 MPH no cruise control
Refill tank and divide the gallons into the miles traveled.
Tire pressure 35 lbs when cold
Not too much in trunk

Short trips frequent stops and starts kill MPG quickly

Telcoman

 

I by accident put 87 in one day and never again. Worst gas mileage ever.