2009 Galant, 31k Odo, bad gas mileage

2 tanks ago I installed an Injen MRI (Megan Ram Intake).. before you flame me with all the heatsoak shoulda gone CAI, this is mainly the car my Wife drives, and I'm from Washington State where it rains 85% of the year.. so self explanitory.. anyway just on this tank I noticed my gas needle moved at 24 miles since fill up, and it usually doesn't budge until at least 70 or so.. also there was a notice in mid range power decrease.. not what should be happening from a less restrictive intake.. I thought just having the positive off would reset the ECU while I was installing it.. could this be because I didn't also have the negative off?? do I still need to reset my ECU or could I just have a bad o2 sensor possibly fuel injector problems?? anyone's .02 cents would be appreciated, thank you.

Not sure what a megan ram intake is but I installed injen SRI on my 3.8 ( for the same reason here in vancouver)and I didn't get that problem. Could be an O2 sensor or MAF. No CEL?

lol I meant to put *Mega.. it's the same thing you stated.. short ram, just injen also calls it MR "Mega Ram" technology lol.. but yeah I don't have a CEL which is odd.. and I don't think it's the MAF I double checked it today and it's not lose or anything so it'd be a weird coincidence if it went out when I changed the intake.. guess imma check the 02 ... i was thinkin it could be bad gas but we'll have to see

start by reseting the ecu then let the car idle for 10-15 mins you changed stuff and the computer is still running like it's stock. After any mod it is best to let the ecu recalibrate and sometimes it can take up 100 miles for this to happen.

Ya try resetting the ecu. Disconnect both terminals. And follow instructions above. There should be a thread here about resetting ecu or try club 4g

To reset the ECU just unhook the negative, then positive, and keep it off for about 15 minutes or so. While you're waiting double check to make sure everything is connected, all the couplers are secure, etc. Then when you reconnect the battery, turn the key to "on" but don't start the engine. You'll hear clicking and what sounds like a robotic arm turning. Wait about 15-20 seconds. Turn the key to off for about 10 seconds, then start the car and let it idle for awhile.

Although I don't think this is causing your gas problem. Since it's your wife's car, do you think she could have put in the wrong gas? Gas from a crappy gas station? Etc? Does she let the tank go down to almost E every time before she puts new gas in?

I'd get some of the fuel treatment stuff and put it in the gas tank for the next batch you get. Maybe even get one of the little units you plug in to your computer to read error codes. Even if you're not throwing a CEL or others you could still have something going on that would show up once you plug the car in.

Well I reset it yesterday.. so we'll see what happens.. hoping it's not something else

i learned touching the wifes car is pointless especially if there not into cars. spend the money on your car instead, less headache that way. hope it gets resolved.

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Originally Posted by krazienluv10

i learned touching the wifes car is pointless especially if there not into cars. spend the money on your car instead, less headache that way. hope it gets resolved.

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Excellent point my friend.

Yeah.

haha krazie

Quote:

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Originally Posted by krazienluv10

i learned touching the wifes car is pointless especially if there not into cars. spend the money on your car instead, less headache that way. hope it gets resolved.

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LoL. Very true, stick to OEM parts on their cars so they last and no problems arise.

Make sure that filter is clean yo.....just cuz its "new" doesnt mean it wasnt sitting on a shelf collecting dust...or maybe your wife rallies in it when ur not around and got it clogged with dust and debris...and make sure you hooked all your hoses back right