Hello Guys,

Had a very weird experience today. I tightened the throttle body (you know, adjusting the two screws holding the throttle cable on the bracket), but now the car's mpg is the worst ever.

Before, I usually have around 29-31mpg during highway driving, more like to 29 if I am cruising around 75mph+. Now, after taking a 400 miles trip, the mileage is down to 20mpg (cruising at 65mph).

Any insights of what's happening?

 

i'm starting to face the smae problem, but i'm not completely sure that the problem is directly related to the throttle cable.

I also have to change my plugs, and i'm coming up on an oil change. It may just be my car, but when an oil change is due, my MPG drops tremendously. Also, i have a CEL, so the car may be running bad due to that. I'm also thinking that this evil bitterly cold weather may have something to do with it, especially considering that for the most part, our cars spend 75% of the year in weather that's a lot warmer than this. Maybe it's the ECU compensating for the weather. Maybe because the throttle is tightened, you're giving the car more gas than it needs, and you need to adjust your driving stlye.

 

i really douqt that your throttle cable tightening has anything to do with it unless you tightened it too much and raised your idle .. probly more to do with the fact that in the winter time you have to let the car warm up when its cold at least a little and that kills mileage just sitting there idling even for a few minutes... me personally unless im going on a long trip dont even bother with the mileage im mostly in town and i have a heavy foot oh and i havent been using the max much i got a 4x4 for that so i been letting it sit mostly, i take it out when its nice and roads are dry ,,i also think that they do something to the gas in the winter and that doesnt help the mileage either .

 

Gas during the winter (in the colder climates of the US) contains additives which make the engine run more smoothly and aid in pollution prevention. Check out your states pollution control agency's webpage for the additive requirements of gasoline during the cold winter months.

 

Hello Guys,

Same as you...I did not think that tightening the throttle cable actually worsen my mpg, especially since I did not change my driving style, and hardly put any gas on it.

Oil change might be well in sight, but it's still about 500 miles away since I am using Auto-Rx. I will change my oil shortly and update this thread afterwards.

 

I re-loosen my throttle cable (mainly because I did not feel increase in throttle response in any way, nor the car is more responsive, etc.), but the mpg is still bad.

23mpg in highway (99%) and city (another fill up)!

Do you guys have any idea which system I should look?

MAF
O2 sensors
EGR
Rear (after cat) 02 sensor
Plugs/Fuel Filter/Injectors/Coil packs
Oil thickening/Auto Rx (had this problem before, mpg drops to 25mpg due to Castrol Syntec used up to 8000 miles)

The car is due for 60k maintenance in 4000 miles, and it's only 300 miles shy of its scheduled oil change (Auto Rx).

I know the temp here in WI has been very low, but I drove to Indiana and back over the weekend and the temp ranges from 0 to 45 F, giving the same 23 mpg.

What's the symptomn of bad MAF sensor?