Recently I have been running with Maxima. Lost some and win some. Few I lost are the ones that's pretty modded with most of the bolt ons. I modded to the point where all I need is force induction then I am set. I raced a max, that's modded pretty close to mine, but he doesn't have the flywheel nor a straight pipe in placing of the cat, and I lost. From that I came up with the conclusion that my car is slow. I wrote in other maxes before, and I can feel that they are much faster. I am thinking is my spark plugs (bosch+4) which i just placed around 4 months ago. The car seems to run alright during just normal driving. I haven't replace the pcv valve yet. I hear whistling noise from my engine bay. I checked if it was my CAI or not, by just listening to the engine while pull the throttle cable, and it really doesn't seem like it's from the intake. I never heard that noise before with my CAI, so I think something is leaking. I need suggestion on what should I check to my make my car perform better, and if i really need to take it to the dealer please help. thanks!!

 

i bet you any money.. you throw some NGK Coppers in that baby.. change your fuel filter and she will pep right up

 

yeah..i was thinking about the plugs too hehe... going to get NGK Platinum soon =) already got my fuel filter done hehe.. any other suggestions? thanks sprint..i knew i can count on ya

 

Sorry to hear that. Sell me your 5spd tranny.

 

never! i love my 5 speed...but need to take care of my engine first =\ anyone got any idea where the whisteling sound might come from?

 

Actually the CAI does make a whistling sound at certain RPMs. It's normal, do a search and you'll see. But just to double check make sure there are no leaks on the intake piping and around the MAF.

 

Hey Steve.
Wrap your intake where the pippings connect and see if the noise goes away.
Make sure all the clamps are tight.

 

hmm....i'll take a look at it hehe... hopefully nothing is loose =P

 

Steeve, I'll tell you what.

Whsitling sound usually comes from the exhaust if you have the dual tip. Otherwise, you could really have a leak.
Your intake is constructed the way that on high RPMs it could whistle a little bit, while during normal driving it's OK.

Guys are right, try not to use Bosch for Maxima, because of the japaneese heat standards. NGK's baby!!!

One more thing... If you have over 80K on your car, try to adjust you throttle cables, make it more tight, but not too tight...
I've just done the whole procedure on my car, had pretty much same problems.
Now it's a lot better. Clean the fillter. CAI works great, but gets dirty fast.
Let me know...

 

Definitely, get rid of those Bosch+4 plugs.

I took those plugs in to the dealer to have them installed only to have the senior mechanic on duty totally freak out on me...
Told me that he had two other Maximas come back after a few weeks of using those plugs due to driveability issues.

Due to the "+4" design, the flame front is different than a standard plug. Might generate some acoustic resonance that affects the knock sensor which makes the ECU relax the timing and you lose power. Or it might cause some actual pre-detonation due to a faster propogating flame front...


Those kinds of "hot rod" spark plugs are good for those old school cars with carburetors and fixed cap&rotor ignition -- not for the new cars these days.

cjvurnis

 

Hey Chris!!!

Well, I've had the problem with the Bosch sparks, and it probably did change (relaxed) my timing. So how can I put my timing back to normal?????

Thanx for an answer

 

Two words Knock Sensor...many members on the .org have replaced this part (located under the intake manifold) at about $135 shipped from courtacy and recieved more than a second improvment on there 1/4 mile. You will not notice a bad K/S under normal operating condtions, like your explained, but the more and more mods you get the less and less fast it will show up at the track...in other words every mod you will get, you will not notice any change at the track 1/4 mile time...A bad k/s will send a code back to the ECU to retard timing in turn sucking alot of power away from your foot.
The K/S is the only sensor that will not trip the Check Engine light and in turn you will not know its even bad...The two ways you can find out if its bad is go to a macanic and see if your ECU has been tripped by the K/S code 0304 or test the actual part. Go to the macanic and see if your ECU has been tripped, If it has buy a k/s and replace it yourself, if you have small enough hands

 

Plug will be the first thing I'll change =) Good explaination of the +4 plugs, now I realized how stupid I am As far as intake goes...I hear sound during normal day driving even around 1000 RPMs...so I am thinking something is leaking from my exhaust, since I don't have a dual tip exhaust. I think my flex section is leaking (I have the stillen y-pipe). Throttle cable adjusting sounds good too, I"ll definitely give that a try!. I was talking to Wic yesterday and he reminded that my check engine light is on due to the fact that I did the swap of transmission and I didn't swap the ecu out, and I think that retarded my ecu too I think the timing will change back by itself once the ecu is reset since there is no other way to reset the timing on 4th gen I am assuming resetting the ecu will do so. Here is the things that I am going to do, and I'll report back with the results. I am going to change my plugs, tighten my throttle cable, change my ecu, reset my ecu, and check for bad knock sensor. Thanks for the input you all I love this board

 

Hey steve, change my plugs too

I guess after being in my nearly stock maxima you realized how slow yours is...

Alec

 

you wish alec hehe.... i'll own you any day hehe...

 

Yeah the bad knock sensor is not cool. I gotta replace mine because lately more and more it feels slower and slower. I checked the ECU and sure enough there it was. I wonder why the ECU would not throw a CEL over this.

SuDZ

 

After you do all these mods, man you'll love your car