Bmr4life

I swear something has to be going on with my car. I'm getting 16-17mpg on the highway doing 65-70mph. I'm thinking that I'm running rich and I think a wideband is would let me know that?

Also, I must add that my current combo IS capable of 20+mpg on the highway. I had accidentally loaded my emissions tune with the cats out and got 22mpg on a 80mile round trip to work. Brenspeed says there's nothing different in the tune other than the rear O2s being turned on. Only reason I changed it was to get the Engine light to go away.

tx_zstang

With your mods, you dont need a wideband to figure out what's going on. If the only difference in the tunes is indeed the rear o2's turned off, there should be no other differences.
With your tuner device, you can datalog and see what your fuel trims are doing, and determine if you are indeed using more fuel than your car nominally needs.

2005Redfire6

Also the reading on a wideband only really matters @ WOT.