Ok...I've already posted about this problem, but I have decided its NOT the fuel injector cleaner thats making my gas mileage go to shit. I got my throttle body cleaned by my mechanic since I didn't have enough time to do it myself. I know that there are sensors in the TB, and I was wondering if having the cleaner sprayed on these can mess them up and affect the gas mileage on the car...I had heard something like that before but it didn't affect their gas mileage, just the idling and my car is idling fine. I have about 130 miles to a little under a half a tank, i usually get around 350 to a tank. HELP!

My poor car is always sick. I think it was problem-free for maybe 3 weeks out of the past 6 months I've had it. I still love her though

 

I've spayed mine out twice already and no problems(I drive the same 100mile round trip everyday and always calculate MPG when I fill up)
Is your air cleaner clean? or possibly damaged? the cotton or foam cleaners can get damaged during improper cleaning and basicly close-up,melt,whatever and you wouldnt know it.

 

i wouldnt clean my TB. it doesnt get dirty enough to reduce any thing. yes it will get black looking but thats all.
its possible that a sensor got damaged durring the cleaning. the other thing to think about is that gas stations are starting to use winter blends and the commonly reduce effiecency

 

ya true dat on the winter blend, but many get sticky gas pedal or irratic idle which is caused many times by a T/B with build-up of the oil vapors coming thru the PCV into the intake hose.

 

How many miles are on your O2 sensor?? If it's over 60k it's time to change it (the primary one).

 

I think most of the throttle body cleaners or carb cleaners are safe for the sensors.

 

This is the first I've heard (read) about that, can you give more info on this?

 

Is that a recommended change like you would do for the timing belt or something? I thought we only change them when they go bad.

 

hmm, my gas pedal is hard to press on when it comes to a complete stop.. i have to add a bit more pressure than usual to get the pedal to accelerate.. and sometimes it won`t acclerate so i add more pressure and when it accelerates my car boosts so quickly, it doesn`t accelerate gradually, is this a case of the throttle body? also, my last full tank, i got 310.. is that good? 40% city 60% highway.. i fill up with Shell V-Power

 

hahaha ya man that IS your TB, no doubt! if you're a do-it-yourselfer then just go to the parts store and get a can of tb cleaner( I use "Valvoline synpower carb and tb cleaner") take off the rubber intake hose at the TB and look in there w/ a flashlight it'll be brown around the egdes of the butterflies. spray it and wipe/rub it all clean and there you go no more sticky pedal. This is tried and true method, dont worry, when you start her up it'll run rough for about 10secs but then it'll be perrrrrfect.

BTW the sensors in the TB also get built up w/ this junk so instead of having the dealer replace them when they're clogged, clean them in the above proceedure.

 

If the mpg is doing to the dumper then the CPU defaults to a rich mixture to keep from burning up the valves if it went too lean. It may be that his O2 is on it's way out. If he has access to code scanner that can also view systems in real time it may show a rich condition and/or the CPU not getting a signal from the O2 to make some adjustments in fuel delivery. The O2 is a little generator that sends the signal only when it gets hot enough, if it's bad it won't generate any signal at all. That's why mpg really sucks if you only do short trips with a cold engine.

There really is no scheduled time to change an O2 but anything after 60k is usually borrowed time.

 

A stuck TB could be a result of sticking plate inside the bore or the spring assembly on the outside. It happened to me 2 years ago. The gas padel wouldn't move and I had to apply more than usual force to get the car going at stop. Every time, the car lunged forward. I used lubricant on the springs assembly area and operated the TB by hand. After couple of spraying, the problem went away. If the area you drive in is quite dusty, gum and dirt would make your TB's spring to stick. That's at least is my experience. If that doesn't cure it, probably it's inside.

 

thank you for the reply and help =) appreciate it, probably going to check it out sometimes soon..

 

Is your cel lighting up? The reason I ask is I just replaced my TB due to a bad sensor. Buy a OBD II reader. They are about $100. If you get code P0122, it's your TB sensor and it is a warranty fix. The ensor is not replacable, you'll need a new TB.

 

i just finished cleaning my TB, it was kind of hard taking off the big black hose connected from the air filter to the TB, but i managed ^_^ i used STP throttle body and intake cleaner, 2.85, =D well, the main purpose i cleaned the TB was because my gas pedal would kind of get stuck when i come to a complete stop (see above post).. so i cleaned it today, took a test drive, and the pedal is smooth when it came to a complete stop and then accelerate again.. but cleaning my TB should also improve my gas mileage, right? i`m also planning on buying a new air filter, the K&N ones.. would that also improve my gas mileage?

 

HIGHLY unlikely that it will improve mileage. since the only thing that goes thru it is air. the thing that would affect it more would be a fuel system treatment IE. fuel injctor cleaner. that would need to be in your gas tank in order to get to the injectors to clean them

 

fuel injector cleaner, as in, those bottles where you pour in your car after filling it up with gas?

 

bump

 

yes. the spray that you spray in the tb wont clean the injectors

 

alright, went to autozone today, bought a bottle of STP fuel injector and carburetor cleaner, it was a bottle for a 21 gallon tank. i filled up, 12.4 gallons, poured the whole bottle in there, now what? do i notice the difference right away? or it`ll take a couple of tanks? and do i do this every tank fill up? or just once in a while?

 

You do that every once in a while, and you wont feel a thing really. I mean its more of a piece of mind doing and maintenance thing.

The K&N filter will help 1-2MPG on the highway, but not much at all in the city. And you may feel some improvement with it.

 

oh okay, thanks for the reply