I was thinking about this thread and make sure you are using proper driving habits if your not, I am a young driver and I drove terribly until just recently , I always accelerated at like 2100 rpm and kept of there til I had to almost like stop just because the engine sounds so good right around there, now when I drive I never let the engine above 1650 and I coast no matter how slow I'm going if I see a red light ahead lol my mpg increased by about 7 no joke, I'm an lt1 driver btw but yeah

 

yeah i don't think i,m driving to bad. a few high revs here and there but nothing completely high. I usually coast too. Thing is I can't afford the 10 miles to a gallon. Thats horrible. have put about 50 bucks of gas in for the week. I really don't know what it is..

 

Does your car sound like it's got a load on it all the time? If you have no engine like it's most likely a air intake problem or a exhaust problem. Something's not flowing.

 

Also a cai kit will increase your milage buy a few mpgs. Same with an exhaust system.

 

could it possibly be the cats? The car did pass a sniffer test at emissions when we got it around a month ago.

 

Do what I do. When I drive, I don't go over 1500 RPM's. Its hard to do at first, but you get used to it. I get great MPG's.

 

^ +1 less than 2000 rpm is good for not drinking up the gas. As i recently learned ....

new air/fuel filter, check all your vaccum hoses, replace as needed, if the pcv valve is gummy with oil, swap it out, next test your fuel pressure make sure it doesnt drop- leave the gauge on for an hour. if it drops, then a injector is leaking or fuel pressure regulator isnt holding pressure, if not any so far, test your back pressure with a vaccum gauge- take out a pre cat o2 sensor and run the car make sure its not more than 1 psi else you could have plugged cats, if still not that, swap out the coolant temp sensor. if none improve mpgs, start saying yur prayers!

if it does help, a thanx to all the guys on here for givin me these tips in the first place!

 

^ +1 on those tests.

 

ok. I'll start with what ive done lol. I'll be getting to work on these all day tomorrow I hope. If none improve the MPG the 'maro might have to go up on sale =/ really what i do not want to do. I favor the updated interior but this car has grown on me so much lol.

[X] Air filter (if duke of oil counts. they did it.)
[X] Fuel filter
[ ] Check Vacuum Hoses (How would I go about checking them all?)
[ ] PCV Valve Check
[ ] Re-Check fuel pressure (Leave the car running for an hour or start then shut off?)
[X] 2 New injectors, 4 cleaned, didn't see leaks at that time
[X] Replaced Pressure Regulator
[ ] Test Back pressure
[ ] Coolant Temp Sensor

Thanks to all of you guys so far. Without you guys on here this car would have been a nightmare lol

ALso, my car has 2 differant size tires according to my dad. Would this affect it drastically?

 

No the 2 different sizes would only affect handling. Just look and feel to make sure the vacuum hoses are in good condition a connected tightly. For pcv valve just replace it. What kind of air filter do you have? A k&n filter can be clean and also help improve fuel milage. Also fill your tires to the recommended tire pressure. Normally a few psi bellow max if not the same size as what your car says on the drivers door other wise the recommended psi is on the door.