Ok, well I have a 2000 Chevy Blazer 4dr 4wd 4.3L Auto. It was just tuned up about 2 weeks ago when I bought this blazer. New battery, rotors, brakes, plugs, plug caps, plug wires, plug spider (I think that is what its called) oil change, and anything else they do on a general tune up. I am not sure about air filter quality but I was told it was good. I did however buy a gas mileage chip for my blazer. It came in the mail and all it is is like a resistor. What you do is form it into a u shape and unplug the IAT sensor (this monitors the air coming into the carb?) then with the u shape resistor (chip) you shove it into the end of the IAT sensor cap so I guess this makes the computer think its still working fine. My guess is that the computer then leans the engine out which gives me better gas mileage and hp like the auction says? Is this ok for my engine and how does this little resistor actually work?

 

The function of the resistor is to trick the PCM into thinking it is getting a specific air temperature. These are all a hoax. The chip will work for a short time, then the PCM will start to ignore it's reading because it compares the values of other sensors to verify the proper operation of the engine. The more you drive it, the less it will have an affect. And trust me, it doesn't last long enough for you to tell at the pump.

 

So what do I do to get better MPG? If a resistor wont do it, what will help?

*Combining consecutive posts*

Would this help me any?

Ebay Link

Also since I have almost 29 inch tires on the blazer would this give me different gpm readings? I am getting 12 gpm at the moment.


*EDIT by swartlkk* - Combining consecutive posts. Please use the edit function to add additional information if another member has yet to reply

 

I do not think that would show any appreciable increase in mileage.

With 29in tires, if you haven't corrected your speedometer/odometer, you may be calculating your mileage wrong. If your stock tire was a 28" tire, your speedometer will be 3.3% slow. Your odometer will also be low by 3.3%. So if you have traveled 250 miles on the odometer, you actually have gone 258 miles. Not a great difference, but it all adds up.

Also, if you are not running your tires at the recommended pressures, you can lose mileage. Having good, clean, and well maintained engine/transmission/drivetrain always helps.

Things I would recommend having no idea of the prior maintenance of the vehicle would be new plugs, wires, cap & rotor. New upstream AC Delco O2 sensors if your truck is over 75k miles and they haven't ever been changed. Cleaning the EGR valve, MAF sensor, and Throttle body. Possibly a seafoam upper engine treatment (should be done before the replacement plugs are installed. This is all maintenance items that will help your vehicle run as best it can.

 

I am getting 12 mpg though, this is horrible. Is it running to rich? Can I bring it to a dealer just to have them tell me whats wrong, then I can decide what to do from there?

 

A dealer will charge you to tell you what is wrong. What is the maintenance history on the truck? How long have you had it? How was it treated?

 

I bought it from a dealer 2 weeks ago. He did a full tune up from what I was told. I can see he put new plugs, caps, spider, rotor on and new battery. It does have a salvage title. It was hit on the rear right coming in from the front. So I cant imagine it could have affected any serious part. They fully re did it though and you would have never noticed it was in a car accident. I just got some pills from my neighbor that will improve my gpm and hp. He has tested them on his vehicle and I guess it works wonders. You guys got any say on this?

 

Again, snake oil. Not worth your time to pull off the fuel cap. I have read so many independent reports on these mileage improving schemes that disprove them all that it isn't even funny.

 

So in my situation is there anything I can do to improve my gas mileage. I am getting desperate for solutions.

 

You may have a restriction in the exhaust, depending on the mileage the catalytic converter could be clogged. I'd start with checking the O2 sensors and cleaning out the EGR valve before replacing the cat.

Depending on where you drive, how you drive and the final drive ratio, 12mpg may not be all that bad, most people here are lucky to get 20mpg on the highway.