Blown MAFS...again

i was bringing my friend back to his house and was coming around a turn when all of a sudden the car started bucking until it went down to 2400 rpm, and the shit won't idle lower than 1000 rpm and won't rev higher than 2400. this is the second damn time. last time i was wide open on the gas trying to show my intake off to a friend, this time i was just cruising barely over 3K. what a load of bullshit

Thats bad, :cya: how far were you from your house? How fast could it
go if it wont go past 2400rpm's? Still has warranty right?

i could go upwards of 55-65 cuz it's 6 speed but it's such a pain in the ass cuz i usually shift around 3K and every time i'd go toward the 2400 range the car would stop pumping fuel, so it just starts bucking and jumping. I'm thinking of selling it and getting something that doesn't fuck up all the time. maybe a toyota or bimmer. one day my warranty will end but the MAf could still blow and nissan isn't doing anything about it.

uh, i just went outside and started my car and the shit works fine. what else would cause my car's ecu to go into safe mode like that? is it possible that mositure got on the MAFS and froze or something? it was only 4 degrees outside when it happened.

It's gotta be your intake, dude. I run my Max pretty hard, and I have yet to have any problems. I've been thinking of an IS300, and slapping a turbo on it. 300HP RWD 5-speed with Lexus quality and reliability? Fuck yeah, any day of the week. Don't get a bimmer, costs waaaaay too much to repair.

Question on the MAFS thingy..My Maxima is exceptionally poor on gas and I have been told it could be the MAFS on its way out, causing the car to run either too rich or too lean. Could this be a symptom? How much is an MAFS? Or should I start with the O2 sensors?

I would say 02 sensors. Is your check engine light on?
Our 96 five speed Maxima was like a battery powered car
it was so easy on gas, even driving it hard. Now our 98
Maxima with an automatic, isnt very easy on gas, if anything
its bad for a Maxima, but the check engine light or nothing
has ever came on.

Did you replace the O2 sensors on your 98 and see any signs of improvement in the mileage? How many miles on your 98?

I have a friend who has a 99 Maxima and he gets phenomenal mileage, like you described with your 96. I think something is wrong with your car too if it is that bad on gas.

It was bought with 40,000 miles 3 years ago. Nothing like that was
ever replaced, it has 188,000 or more, I havent drove it in a few
weeks, but it runs perfect. Its had this kinda gas mileage ever
since we bought it, even after a tuneup from Nissan at 125,000.
We were told from the service that the mileage was normal for
automatics. We told the service guy that autos and five speed
Maximas were supposed to have almost the same gas mileage,
(from Nissan brochures anyway) , so they did check it out and
said everything was fine. I dunno, maybe yours may be going
bad, but I always thought the check engine light came on if
they were bad. The check engine light has never been on in the
98 Maxima.

Would you be able to tell me approximately how many miles you get to a full tank of gas, under normal driving conditions?

my car has the same problem...i put a injen intake on it and it hasnt ran right since then...now i have to find a mafs connector...and thats not to easy to get

Would you be able to tell me approximately how many miles you get to a full tank of gas, under normal driving conditions?


On trips it gets around 24 mpg, and 18 19 mpg city.
The 96 got 31 32mpg, and 24 25 mpg city driving.

What is your Maxima getting? :grinno:

The tank is 18 or 18.5 gallons I believe. I fill up with Super and get about 210-220 miles to a full tank. So thats about 11-13 mpg city or highway, it doesn't matter. It is unbearable, I can literally watch the guage go down. :disappoin. But there are NO lights on saying there is something wrong with the car. :rolleyes:

when you punch the gas you can see the fuel gauge drop right? well, if so does it tend to climb back up a lil after you return to normal driving?

when you punch the gas you can see the fuel gauge drop right? well, if so does it tend to climb back up a lil after you return to normal driving?



Of course it does, just due to the gas moving around in the tank. :smile: What I meant was I can literally see the gas guage change positions on short trips. IE from work to home (about 7 miles), it will move permanently. This thing is really sucking fuel bad. Today I changed the fuel filter and cleaned the throttle body, doubt it will help but it certainly won't hurt.

i was just seeing cuz my friend had a jeep and the fuel return became disconnected from offroading so any fuel sent back through the lines wasn't being brought back it was just being spilled. it drastically lowered his gas mileage.

The tank is 18 or 18.5 gallons I believe. I fill up with Super and get about 210-220 miles to a full tank. So thats about 11-13 mpg city or highway, it doesn't matter. It is unbearable, I can literally watch the guage go down. :disappoin. But there are NO lights on saying there is something wrong with the car. :rolleyes:

I thought that our 98 was bad on gas. Something else must be
wrong with your car. :disappoin I asked our service guy today about the 02 sensors in Maximas, and he said that even if they go bad you
shouldnt notice much of a gas mileage differece.

I appreciate you asking your service guy....But be sure to tell him, he has no idea what he is talking about if he thinks a bad o2 sensor won't effect gas mileage. Honestly, I can't believe some of the crap these people at Nissan come up with, it is like they receive no training. The o2 sensor has a BIG hand in deciding how lean or rich the car will run, so it WILL effect gass mileage, as will the MAFS.

I dont know, Ive never had it happen just once in 96, and it was
replaced right away under warranty. :grinno:

i've been getting an average of 300 miles per tank since i bought the car new.
it's not the best, but i hasn't gotten worse since i put an intake on.
skids why don't you bring the car to the dealer, maybe they can diagnose the problem for you.

it sucks that there is no CEL on. that would make it 10x easier. it could be a lot of things. fuel filter. fuel pressure regulator, fuel pump, 02 sensors, your catalytic convertor could be clogged. piston rings, injectors, spark plugs(although you say the car runs fine) coil packs, throttle body, MAFS, your timing could be off.

i was bringing my friend back to his house and was coming around a turn when all of a sudden the car started bucking until it went down to 2400 rpm, and the shit won't idle lower than 1000 rpm and won't rev higher than 2400. this is the second damn time. last time i was wide open on the gas trying to show my intake off to a friend, this time i was just cruising barely over 3K. what a load of bullshit


The 2002 MAFS is a known weak spot on the Maxima. Get the updated part number and replace the sucker. This is a well documented problem with several hundred dealer replacements from Maxima.org alone...

I have replaced the fuel filter, air filter, PCV Valve, Fuel Regulator, plugs and the rear O2 sensor up to this point. The fuel pump is fine. Have not checked the catalytic, doubt it is clogged at 29,000 miles, and I would probably be losing power if it were faulty, but anything is possible.

I went to the dealer today and they said there is nothing wrong with it. That is after I ran a tank of gas and got 14.4 MPG. I went 228 miles on 15.8 gallons of fuel. I will try another tank from another gas station and see what happens. Maybe I got a bad tank of gas with too many additives (doubtful) or maybe the really cold weather (negative temps) we had last two weeks has a greater effect on the car than I thought. My 03 Accord V6 had no noticable problems with gas mileage in the cold though so I doubt that is it either. Who knows, it looks like I might be chasing this for a while. Thanks for all the suggestions, keep em coming! :)

The 2002 MAFS is a known weak spot on the Maxima. Get the updated part number and replace the sucker. This is a well documented problem with several hundred dealer replacements from Maxima.org alone...
yeah, i've been there already. that's why i put the "...again" in the thread title. it ended up just being a fluke thing cuz the car's been running just fine ever since the day after the incident. i'm thinking since it was snowing i sucked some moisture in my intake and it froze on the sensor. that or the filter itself got wet and froze and air couldn't pass through. right now i have an 03 mafs that nissan used to replace my 02 under warranty, but thank you anyway for the help. and this is no longer my thread. skids came through and hijacked it right out from under me. :nono: :smile:

and skids man, have you tried running a fuel system treatment like STP? maybe you just have some build up.

i was bringing my friend back to his house and was coming around a turn when all of a sudden the car started bucking until it went down to 2400 rpm, and the shit won't idle lower than 1000 rpm and won't rev higher than 2400. this is the second damn time. last time i was wide open on the gas trying to show my intake off to a friend, this time i was just cruising barely over 3K. what a load of bullshit



Yo man my buddy has a 02max and has the stillen intake on it and his MAFS went twice two. the same exact thing happend to him with the friggen car going into safe mode. its because water is gettin into it due to having the intake. water is gettin up into the MAFS now becasuse the stock air box isnt there to block the water.......... either make a shield to block the water or put the stock intake on. it isnt even that much horse loss so dont worry......... my buddy put his stock on back on and now has no probs with the damn MAFS........

JUStin

Dude, this thread is almost 1 and a half years old, not really relevant at all. Old threads = don't dig up from the grave

1) this thread's old, but it is still an unresolved issue and it's still my biggest gripe about the 5.5 gen maxima's.
2)can't say for sure about your friend, but in my case it wasn't because of water, it was because the aftermarket air filter had too much oil on it. switch to an Apexi filter, which doesn't require oil, and you'll be all set. don't use foam filters.

i was bringing my friend back to his house and was coming around a turn when all of a sudden the car started bucking until it went down to 2400 rpm, and the shit won't idle lower than 1000 rpm and won't rev higher than 2400. this is the second damn time. last time i was wide open on the gas trying to show my intake off to a friend, this time i was just cruising barely over 3K. what a load of bullshit


my car goes through the same shit. as long as i drive the car good it wont mess up at all as long as i just drive it hard once in awhile. but once i start driving it hard more often then it starts to choke like you described...and this never happened before i had my intake on it

I had issues with my 95 maxima when i put an intake on. i got a CEL, the idle was lumpy at times, and there was occasional power loss. you know what actually fixed the problem? that Tornado Fuel saver thing you put in your intake piping. i can't explain why it worked, but all the issues i was having went away and never came back.

I had issues with my 95 maxima when i put an intake on. i got a CEL, the idle was lumpy at times, and there was occasional power loss. you know what actually fixed the problem? that Tornado Fuel saver thing you put in your intake piping. i can't explain why it worked, but all the issues i was having went away and never came back.


lol thats a riot pao cause everyone claims that tornado thingamajiggy is the biggest hoax.

lol thats a riot pao cause everyone claims that tornado thingamajiggy is the biggest hoax.Damn, man, i haven't seen you posting for a while. how's life? and what'd you call me? :wink:, j/k.

anyway,
i can't really say if it improved mileage or power, so it may be a hoax in that respect, but my problems with my intake went away on my 4th gen as soon as i got it. maybe it increased the air pressure in my intake piping or something, which made the CEL go away and made the car run better or something along those lines. i really don't know.

hey bro you know i'm old skool and i like treating my old friends with old names.. lol.. anyway things are great bro the max is running great and i'm busy at work. too bad i have no money to sink into the max but i love it everytime i crank it on. i'm always ghosting around the forums so just give a shout out anytime. I hope the ride is running good. peace.