-2003 vq35 6 speed
-ever since, and only AFTER short ram intake, my car has WOT problems
-it pulls to 2200-2500 and hits a spot where the revs get laggy and unstable
-it may/may not find the right pull again, and then it gets lag and power loss around 4000k and picks up again
-from a 2000k or similar low rpm pull, its the worst
-from a cruise speed like 70 and i go from like 6th to 3rd, it pulls fine, not really noticeable
-ive already changed MAF.... TWICE.. cause i thought i was so sure that was the problem
-only after intake install

any guidance would help, as im on the edge of dropping it off at the dealership.. which would suck.

tried searching, all i got was maf, or clogged cats, but this aint me.
maybe a knock sensor? bad ecu?

 

no codes?

 

Ive had the similar problem when my only mod was an intake. I thought it was heat soak to be honest.

 

well no CEL

will get codes checked asap

 

put the stock intake back on and see if the problem goes away

 

Exactly!

 

this

 

How many miles does your 03 have? Could be a lot of issues going on...when was the last time the fuel filter was changed?

 

Check to see if your o2 sensors ad wires aren't damaged, mines was like that for like 2 weeks and I couldn't figure out WTF was going on with it, after giving up and paying the mechanic found out that my o2 sensor wire was damaged and that took him like an hr to figure out.....

 

Half of my O2 sensors aren't even plugged in.

 

To be honest, I think we're overlooking the simplest potential cause. Verify there are no vacuum leaks or hoses that are incorrectly connected. The stumbling really sounds like you've got unmetered air entering the intake. It probably isn't that big of a leak and may take awhile to find. I had a 4th gen with a similar stumbling problem in the low and mid range a few weeks back. The bracket for the cone-filter housing was pinched in between the housing and the MAF underneath. It took me a while to find it. It was very well hidden and the gap was barely perceptible. Corrected the bracket and the DE went to revving like a champ. I just think it's too much of a coincidence that this started as soon as you changed your intake setup.

 

The wires with mines was damaged and it would sputter to 3400 where the ecu don't read the o2 sensors nomore then acts normal

 

I agree. ...
Srsly. All it takes is a simple 2-4 minute visual inspection of the intake.

 

I hacked up the factory airbox to scavenger bolts for my maf converter plate, I realized that was dumb too late.

Car is immaculate and well maintained, plugs and filters are all fairly new

There's only one hose that goes to a 5.5 intake, and I have it hose clamped to a nipple that goes into a grommet/bung on my intake pipe, air could be coming thru there i will check on my lunch break in a few min and post back.

Hustle, I find the 5.5 maxima exhaust ten times more complicated than any exhaust manifold system I've seen, but I'll check the 02s also

 

Why not just do what knight suggested and if it fixes the problem you can steer clear of the exhaust system and re-think your intake endeavors a little more thoroughly.

 

Good idea, but...

 

I want to n wish I could, but I cut a bunch of bolts off the factory intake so i can't mount it back up, I've also had my gf move in w me and take over my parts room, so most likely sheeet be missin

I'm 21 y'all cut me some slack

 

measure twice, cut once

 

 

I have a ported stock airbox if you want it. This one actually works.

 

Nmex, if i cant fix it thru the help on this thread, ill shoot you a pm.

took some vids and pics, upload as soon as i get off later.

took the intake completely apart on my break, reattached every hose clamp, coupler, etc... doesnt appear to be leaking.. but im still goin to take some carb cleaner and spray around the gaskets. a tech here at mercedes benz where i work said carb cleaner will make ur rpms rise because of the combustability, if thats a word, and thats a way to check for air leaks..

pics and vids coming within a few hours, and thanks for yalls help, this is making me want to sell the dern thing...

 

bout to take my intake apart again, im leaning toward what neledge said, leak in the intake, unmetered air is getting in. just found out car has NO CODES.. still looking for help on this...

 

sounded similiar to me... i was going crazy the other day... bought a junkyard ecu, brought it to the dealer to get my key programmed to it. fixed everything

 

no leaks anywhere, ill try to post this vid.

 

take starting fluid (ether) and spray around the engine bay where you think there may be a vacuum leak.. and if the idle jumps up you know you've found it.. if you don't have ether use x throttle body cleaner.. just listen for the rpm's to decrease; either way works..

 

nevermind.. i just realized someone already suggested that to you lol

 

in this particular video/pull, the car doesnt pick up good until after 4k rpms, then pulls perfectly fine in 3rd/4th...

 

http://s458.photobucket.com/albums/q...t=IMG_0077.mp4


EDIT : this is a direct link lmk if it works

 

you needs a new clutch. sorry for being off topic.

 

mehh need one, no.

could use one , yeah.

 

I'm not trying to wreck your thread but it's never a good idea to romp on you car with low fuel.. Affects A/F..

 

its not heat soak, it does it even when the car is cold

still havent found a leak

any way i can rule out it not being the KS? knock sensor*