idk why it does that, its quite annoying.

 

From what I can gather, it's the long term fuel trim compensating.

 

i hope so

 

ECU is supposed to maintain a certain A/F ratio, however... if one of your sensors is malfunctioning, your ECU will flip out and tend to run very rich. I have test pipes on and so my bank1 and bank2 throw an emissions code to the ECU (common sense.. Cats limit emissions and restricts air flow to clean it before dispersing exhaust.. if cats are gone and pipes are straight, then the passage way is open and the air can flow more freely.. 02 says, HEY, wait a minute.. this is TOO much air flowing down this section, tells ECU, your sending too much air,not enough fuel and thus ECU shoots more gas into the mix causing your MPG to join the Hummer Club)

Car will not "run lean" after resetting the ECU. your just delaying the inevitable -- it will ALWAYS go back down (in terms of MPG) if your driving with a lead foot or have some mod that interferes with the normal operating parameters that the ECU was programmed for (NO, I don't mean that your pop charger is killing your MPG either.)
__ in short, if you're that concerned about MPG, go get your car tuned or buy a piggy-back and set your ECU to run leaner to save on economy.
Save yourself the headache of running in circles.
Only things that matter are:
1.Your Right Foot
2.fuel (make sure your using the proper grade-PREMIUM-- Premium burns slower then regular or plus fuels,keep that in mind next time you want to save yourself the lousy 40 cents total!Also, the ECU map was specifically designed with premium as the intended fuel to be operated with)
3. performance of your Engine (incld functioning of Sensors and cleanliness of things such as filters, oils, internals,etc..)
4. Tire pressure

"Octane Boosters" and fuel conditioners are ALMOST all BS products! In fact, the use of some particular fuel products can actually decrease your MPG or cause your fuel to burn improperly (in some product testing, it has been discovered that particular agents could actually clog your fuel injectors rather then clean them-- Like I said earlier, don't be cheap and spend the extra couple cents for the proper fuel instead! )
If you're really intent on using a fuel or engine cleaning product, I suggest SEAFOAM for your engine (you can seafoam your vehicle by allowing your vacuum line to intake the chemical)
Seafoam chemical will trap your carbon build up in the engine and force it out the exhaust system. You can also add it to your oil (it will help remove sludge build up and you can drain it out via oil change) or you can pour it into your fuel. NOTE, don't go crazy with this stuff either! Read the instructions as it's very specific as to what amounts go where.
I've tried using LUCAS products in my vehicle as they have a long established history in the automotive field-- however, when I used their fuel stabilizer, my MPG decreases substantially and my vehicle experience a CEL.


Regarding Tire Pressure: some of you were saying that 35 PSI is 35 PSI.. while that is correct in theory, it should not be used to argue whether it is OK to put more or less air in your tires. Depending on where you live, the air pressure may need to be adjusting (increased or decreased) to account for temperature change.
I.E. if you live in an area where it is colder, your going to want to increase your air pressure b'c the air in your tires is contracted due to the temperature. When it's cold, the air molecules will clump together to maintain the proper density for your elevation.
On the other hand, if it's fairly hot in your area, the air will expand (molecules separate) and that will increase your PSI without you even doing anything.
PSI recommendations can vary and be different from tire to tire and rim size to rim size as it may be necessary to employ more pressure to maintain proper tire inflation on different profile set ups --so not in all cases is it recommended to follow your manufacturer's specs. Read the side of your tire to get an idea of what your range is (I .E . Max 60PSI ,min 30PSI) and adjust to what is most comfortable for your driving style and the weight distribution of your vehicle.

Well.. good luck to those with horrible MPG. I've tried alot of things since I average bout 200MPT(miles per tank) -- so long story short..while the above all influence the car's MPG, the most effective way to control it is through the ECU itself-- via your right foot and/or tuning, not through 'quick fix' chemicals or because you had 2-3 extra PSI in your tires
Hope this helps!

 

So you only get 200 MPT also?? this doenst bother you lol... i guess the ECU or anything wont help thats just the way the car is and i have to live with it because my car is mint.. its an 05 wit 26k and i doubt it has anything wrong with the engine it was service and checked so it is what it is huh

 

Daman, it disturbs me greatly but I know why it is doing such-- the 02 sensor is reporting an error to the ECU..

now, unless your CEL light is on, you shouldn't have it as bad as I do unless something is wrong or your always flooring the gas pedal

 

no thats the thing my CEL is not on and everything is fine thats y i dont understand why im getting 200 per tank.. why dont u get your 02 sensor fixed? ill go get mine checked out to see if the sensors are fine, ive just been lazy lol

 

WTF?!?! Not to be mean, but you don't know what you're missing. These cars were meant to be DRIVEN, not granny'd (sp? or is this even a word, don't care at this moment). Dude, stomp on that pedal and feel your smile get bigger than your face. I have to vote.........Fail! lol

 

For the ones that are worried about gas mileage. Please sell the POS gas guzzler G and get yourself a hybrid.

 

But if you have a higher sidewall, you may need to run a little higher to keep them from squirming.

I am getting a couple bottles of this stuff: I'm a born skeptic, but it has a money-back guarantee to improve mileage. I'll give as objective a test as I can (my driving is sporadic right now and difficult to track) and let you guys know the results. If anybody else wants to try it, PM me.

 

If you need to up the psi due to squirmy sidewalls, you have the wrong tyres on.

 

I have to agree with that. I had some tall Michelins on a 3/4 ton truck and at 32psi it was dangerous, at 40 it was fine. It can make a big difference.

 

What 3/4 ton truck was it?

 

Ford Supercab, 460cid, used it to haul a camper. OP - sorry we're so far OT!

 

I get 19 mpg, driving normally. 13 mpg sounds way too low. I would have a mechanic check for something else.