4cyl turned into a gas hog

[User Name missing]

I have a '99 pontiac sunfire, 2.2 4cyl, with roughly 75k miles. Lately it seems to be using more gas than normal. Besides plugs and wires, what are some of the things I should look at? I'm wanting to change the fuel filter, but havent the clue where it would be or how to change it and Im affraid a shop will charge me upwards to $100 just to change the damn thing. Will advance/autozone run a code scan for free? And air filter has been cleaned recently.

 

[modelageek]

Not trying to be a wise guy but you should join the potiac forum and post the question. A lot of thingd can kill mileage. O2 sebsors. Sparkplugs maf etc etc

 

[fastpakr]

And knowing what you're actually getting for fuel economy is incredibly helpful. The gauge is all but worthless for the task.

 

[modelageek]

Autozone will run your codes for you for free. But likr the previous post said check your mileage accuraly. By filling the tank reset your tripometer. and when you fill up next take note of the amount of gas it took to fill then do the math

Also Costcos sells a good codereader for $35

 

[martin]

The fuel filter is to the rear of the tank, above the rear axle. If you live in the rust belt the connections will be a pig to disconnect. One end is threaded the other end has a quick connect thingy. There is a plastic thing that you are supposed to push in to release it, good luck.

Oh! I doubt that is your problem.

 

[User Name missing]

calculating gas mileage is tricky in this car cause I cant ever fill it up. it wont let me. no, I do not feel like joining another forum to rarely post on or get turned away answerless, which is what usually happens here. how can I lock a topic?

 

[Earl43P]

Poor economy with no other symptom points to an O2 sensor to me.

I'd do the upstream O2 before I'd do wires (mist them in the dark, no arcing, keep them). At least look at the plugs, clean/gap.

 

[User Name missing]

Poor economy with no other symptom points to an O2 sensor to me.

I'd do the upstream O2 before I'd do wires (mist them in the dark, no arcing, keep them). At least look at the plugs, clean/gap.

thanx! are they easy to replace or should I (uhhhg) spend the money to have a shop do it?

 

[modelageek]

They are easy to replace. have the engine a little warmed up when you remove them. it makes it a little easier and hit them with rust penetrater the night before first some times you need a special socket $10. put anti seize on the new one. I never change one on a ranger so not sure if you need the special socket or not. you can order them online for less money. A shop will charge you a fortune. I just got one online for a pontiac vibe installed in 10 min paid $78 the shop wanted $250. they make universal and direct fit ones I like the direct fit but they are more money. I always try to "diagnose the replace" was your cel on? did you throw any codes? an 02 sensor will last about 100k so if you have that mileage or more and they never have been changed it proably is a good idea. but they can cost some cash...have your truck cel checked at autozone for free even if the cel is not on keep us posted