Gas Mileage Crappy

I lose 1-2 mpg on winter fuel. Blaming 10mpgs on winter fuel is extreme. Hence my reply.

The worst MPG I got was 12mpg going 90mph for two hours with extreme headwinds. Even then, it was 12mpg. There is something else going on with his truck.

 

The main one that affects fuel mileage is the fuel/air sensor. That one is just behind the cat I believe, and has a wire running up to the transmission somewhere. I can't remember exactly, it's been a while since I replaced mine.

OP, did you try seafoam? It sounds like you've done everything else. I have not used

$25 BG44K BG 44K Fuel System Cleaner Power Enhancer 11oz.

BG44K but B12 Chemtool and Techron concentrate get good feedback on Bob is the Oil Guy. You may have to get the injectors cleaned professionally if they are really bad, or you'll have to run several doses to clean them. This is why I recommend running a dose on 1/2-1/4 tank, in order to concentrate the cleaner more. Just dont burn through it all at once, you need to let the truck sit and let the injectors soak to get a good cleaning.

 

Don't recall blaming entire 10mpg loss on winter fuel, it was a suggestion to be considered when doing the math.
Again, a contributing factor to be considered along with tune up issues, maintenance, driving habits, weight, tire size, etc..
In fact, there has not been any single potential reason mentioned that would cause a 10 mpg loss. But, a combination of these would in fact be worth mentioning.

 

It's actually the one in front of the cat that matters for mpgs. That's the one that determines fuel/air mix. All the one behind the cat does is make sure the cat is still working.

 

That's what I meant, it's been a while since I changed mine but there is definitely only one fuel/air sensor, that's the main one that should probably be changed

 

That's my understanding as well. The post cat will dump extra fuel on warmup to heat the cat to operating temps. If it starts to fail and reads wrong the wrong way it can potentially continue to tell the ECU to run slightly rich as a means to heat the cat. URD makes a fooler for those deleting the cat to avoid this.

 

Sub, need to do a bunch of these things. Getting 15 mpg with no lift but armored up on m/ts with the 3.4.

 

The post cat sensor only monitors cat function. It doesn't control fuel at all

 

I have a 97 w/ a 2.7. I've been trying to figure out my bad gas mileage for a while now with not much results. I replaced my plugs, plug wires, MAF (cleaned it too), air filter, both coil packs, fixed all vacuum lines, O2 sensors, cat + muffler, cleaned my injectors + intake manifold & plenum, plus probably more stuff that I can't remember.. I Just recently tested my vapor canister and it's been bad for a while with no CEL. I'm going to replace that next week when I get funds. Im hoping that it helps a little but Im not expecting it to do anything really.. I get close to 15mpg half city half freeway on 31's (just recently got 33's)

Also just got a deck plate to do the deck plate mod and I also just got an 04 exhaust manifold from camelback toyota parts in hopes that I will gain little bits of my mpg back.

 

PO303 code, cylinder #3 misfire. When I swapped coils #1 and #3 I had gotten a PO301 code. When I moved the coil the fault followed so that's how I came to realize it was the coil pack frizzman

 

cool, I didn't see it mentioned earlier so was just wondering


and back on topic I just filled up today and was at 13.7 mpg with about 70%+ of city driving (my trip is about 5.6 miles, 35 minutes one way )

 

It takes 35 min to go 5 1/2 miles? And I thought Austin traffic sucked!

 

it was a normal rural road that over time became a main artery. Problem is they did not get rid of any traffic lights...