ok i finnaly got around to installing the lower pipe to my PR intake, happy with the fit and finish but ever since i put it in it seems my gas milage has gone to crap. I went 55 miles and now im down to 3/4 of a tank from full (and you know how it goes past full). Usually i get 100 miles at 3/4 mark pretty easily. I also added the monster flow filter(had k&n on) so i have 2 variables here, but i can't see both of those limiting my gas milage so badly. I have fog lights too so i dont know if that is an issue. Anyone have or had similar issues. If this is the norm, im thinking of taking it out.

 

have you been flooring it more to hear the intake?

how long since you switched..give it about a week and see what happens

 

did you start with a full tank? Sometimes when I fill up the Maxima, the pump stops early. It's been happening the just recently, though I think it's more of the pumps problem. Nonetheless, you should see if the problem persists. It might be something totally unrelated too...like 02 sensors, knock sensor, ecu, underinflated tires, dragging brakes...etc.

 

fill it up again, and check it again.

55miles is too low....i get about 60-65miles when the needle finally gets to the F mark

 

its really to broad of a catagory to put blame on the intake, i say give it a week or so and see how it goes. personally, my max cant make up its mind, one week its gets civic style gas milage and other weeks its like an M5. my old max was like that too. anyone else experience this?

 

well i havent been womping on the gas any more than i usually do so i dont know what could be the problem.??

Oh yeah another question. after i installed the intake and went to put the filter on to the pipe it felt as tho the filter is kinda smashed aganist the fender wall which could be restriciting alot of air flow. Anyone have a remedy to this or did i drill the hole to close? (i followed the attached cut out)

Thanks guys for the help so far, ill let the ecu do its thing for the week.

 

try resetting your ecu if you haven't done that already
you sure its 55miles at 3/4??
at that rate you'll get less than 220 miles on a full tank!!
that is pathetic mileage.

i almost get twice as far on a tank, and i don't drive too slow either. i thought my mileage was bad...

might be your knock sensor, cause something is definitely wrong.

 

Well, when you disconnect the battery, the ECU can run rich for up to 40 starts afterwords. This is considered normal, as it is re-learning everything.

From the Nissan FSM:

Customers often complain of drivability problems during relearn stage because vehicle acts differently then before being serviced.

Depending on type and make of vehicle and how it is equipped, the following complaints (drivability problems) may exist:

* Harsh Or Poor Shift Quality
* Rough Or Unstable Idle
* Hesitation Or Stumble
* Rich Or Lean Running
* Poor Fuel Mileage

These symptoms and complaints should disappear after a number of drive cycles have been memorized.

 

It's your fog lights!

 

in my old max, i used to get real bad gas mileage and i had a PR CAI as well, but i always blamed it on the fuel filter....changed it and car got in an accident before i could fully test the problem

i just went out and checked my new car now and its a little on top of the half way mark and i've gone 140 miles...i predict atleast 10-20 miles before halfway so i'm basically looking at a little over 300 miles a tank...is taht considered good?

 

i think our cars should make it up to around 360miles on a full tank...well my car does, and that's before the fuel light comes on...so if i drive my car til the light comes on, it should get 370+ miles

 

Well, purely on highway, the max does 550 miles before emptying out. I did this from Atlanta to Jekyll Island. Luckily, I was able to pull up to a gas station before stalling out. Hitting 83.5 mph as average.

On mixed driving, I fill up after 370 miles, but then I usually have 5-6 gallon left over. So I think 430-460 miles until red light pops up.

Check your fuel lines and seek out leaks. My bro did 15 mpg in highway with his 300Z before he fixed the fuel regulator hoses.

 

That is way way way over spec. The max's tank is 18.5 gallons. You are making 29+ mpg going at moderate speed. Our cars are rated at 27 mpg highway (~65mph).

Personally, I have never gotten 28 or more mpg even going exclusively highway travel. I think ifyou are 22+mpg mixed, that is about the norm