I don't know what the blend is for gas in MI but here in MN it f@#&!*g sucks. From about mid april- oct I get 23-25 around town and I don't gun it to much, in the winter I have been averaging 19-20. My driving style is even slower in the winter because of more crappy weather. Also Mine also goes down because my car stays colder longer and I have a 1.5 mile drive to work.

 

If your getting bad MPG then I think it could be a failing O2 sensor. This happend to me once and I was having the same problem as you are.

If it was bad injectors I think CF_Ninja would notice some performance problems too.

Either way, get it looked at by the dealer.

 

well.. i'll take it to the dealership on friday and give you guys the verdict.. thanks for the help.. I thought it might be some simple fix.. hope it is..

 

cloged feul filter?

 

I was having the same problem. I uesd fuel injector cleaner and it got my milieageback up. plus I have a safc and better fuel injectors

 

check spark plugs and air filter.

since it i a lean code it could be the injectors. try some injector cleaner

 

i looked at my filter and its all peachy... i'll take it to the dealer and have them check the plugs and injectors... but wouldnt it be running like hell if it was bad plugs?

 

Check air pressure in your front tires too. I ran 19 mpg last tank, but I was only inflated to like 25 lbs in each front tire. Inflated to 32 and I ran 24. Yes, I drive too hard sometimes...24 is good for me.

 

I have the RRM CAI installed on my Ralliart and i got the "Service Engine Soon" light and i had my cousin run his code reader and we got P0171 (lean) i had him clear it and i went out and bought some injector cleaner and changed my oil and oil filter (we used synthetic oil). 700 miles later it retured with the code P0171 (lean) i had him clear it again and i did the usual engine routine check and found my oil was a half quart low. I gave her some oil and the light has not returned. I noticed that when my car runs lean it uses more gas. The whole situation has aggrivated me, but i am far to lazy to install the stock air box to take it down to the dealership so i am just running it. I believe that the oil it is using is due to the car just breaking in. I only have 7,000 miles on her.

 

most of the over the counter injector cleaners do more harm than good (leaves little red sand like deposites on your egr valve and on the plugs) dont use them. the lean code is in response to drawing in a lot of air with your cai or sri leaning out the fuel mixture. i had a nitrous backfire once (early testing stages of my current setup) and it blew off my mesh air filter, causing it to throw that code, so make sure that you have no leakes in your intake before or after the mas. otherwise it possably could be your mas or your o2 sensors reading the exhaust gas mixture wrong.

 

i will check all my connections again.. its too dang cold out right now to be tinkering with my car though.. its 2 degrees right now. My tire pressure may be low, i'll get out my compressor tomarrow and fill them up to 32psi. But would low tire pressure really cause that much of a milage drop?

 

Well my "Service Engine Soon" light went on again, this time the oil level is fine considering i filled it 4 days ago... I am going to disconnect the negative battery terminal and see if i can reset my ECU. This light is really aggrivating me...

I left my negative battery terminal off for 10 minutes and then put it back on and started the car, immediately the light was off and the idle was steady at the line just below 1 (before the reset my idle jumped from 1 to the very bottom line...). I also noticed my muffler was just a little but louder. I took the car for a 10 minute ride and noticed that the throttle was more responsive and that the intake seemed to be sucking air differently then bofore, like it was sucking air at the right times now. I should have reset my ECU long ago, but i had no idea how to and or why to. Thanks to some posts here i found out how and why to and now i think i solved my "idle air" problem. So i highly suggest that everyone with the RRM cold air intake to reset their ECU immediately if they experience a "jumpy" idle and or their "Service Engine Soon" light comes on. In fact RRM should give directions with their cold air intake if they do not do so that even says to reset your ECU... because if i wouldnt have came here i would have been at a shop paying for someone to reset my ECU...

 

Double post...

My "Service Engine Soon" light went on AGAIN only 600 miles after the last reset... Once again i will reset the ECU and hope for the best. I hear that "idle air" from the cold air intake causes the light to turn on, if this is true is there anyway to eliminate this? Will the RRM CEL eliminator take care of this?

 

Could be one of the O2 sensors. That's about all I can think of that would kill mileage while not setting a code. They get slow to react but still cycle, so no code.

 

take it to a dealership and have them hook it up to a mut II. it should give them all the readings of the sensors. i have a feeling your running WAY too rich causing the mil to come on!