Gas mileage dropping faster than the stock market, less than 200 to the tank...

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Fless

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I'd be concerned about the cats. Nothing in the data seems to be out of place: fuel trims are good and the MAF value is good.

It would be interesting to see a graph of both upstream O2 sensor voltages to see how much and how quickly they're acting. Not sure if your scanner can do that, but it might be valuable data to have.
 
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YanaCakes

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I'd be concerned about the cats. Nothing in the data seems to be out of place: fuel trims are good and the MAF value is good.

It would be interesting to see a graph of both upstream O2 sensor voltages to see how much and how quickly they're acting. Not sure if your scanner can do that, but it might be valuable data to have.
I will try to see if it does. And definitely will look into the cats. Thank you!
 

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I forgot to ask -- have you pulled a spark plug or two to see how they look? How many miles on them and how long ago where they changed?
 

ZKWBQD

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Before I sell my soul for gas....I have a 2012 Tahoe LT, 5.3 4WD. The truck has a 3.5 inch lift and sits on 33 inch tires. I was getting around 300-330 to the tank. In the last 2ish years, it has progressively declined to where I can barely get 200 to the tank. I do mostly city driving for reference.

I had an intermittent evap code that comes and goes by itself. About a month ago, I replaced the purge valve and charcoal canister. Also did a smoke test, all good. Code hasn't come back. Gas mileage seemed to be improving andddd then tanked..... Back to under 200 to the tank. This tank may be closer to 150-175 with how it's looking. No other codes, truck runs great, no rough idle.

Please help.
Maybe you're buying the wrong stocks. My portfolio was up in February.
 
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YanaCakes

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I forgot to ask -- have you pulled a spark plug or two to see how they look? How many miles on them and how long ago where they changed?
They were changed about 15-20k. The rear ones were questionable.

I am at an all time low....
 
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YanaCakes

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15burban

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Are you leaking gas? You said you can smell gas on start up. Cycle the key to on without starting it and sniff around. You really shouldn't be smelling gas. Salt does a number on the top of the sending units since it never really gets washed out from up there.
 

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