Zack342

iTrader: (89)

i called my mechanic yesterday and i talked to him about ti for a while he suggest i bring it in for a tune up. he is going to clean the throttle body, i asked him to check the swirl valves, he will replace the knock sensor, new plugs, fluids and pretty much make sure everything is in good shape. the air filter is brand new and i always use 93 octane plus every other tank i use stp inject cleaner. so maybe the car just needs a tune up and knock sensor......
thanks for all the help everyone.i will dyno again in a month and let everyone know how it goes

Zack342

iTrader: (89)

i am going to guess its the knock sensor. i have been doing a great amount of reading on here and all signs point to know sensor, especically since the poor power starts around 3500rpm and goes all the way to redline. i don't think the sensor has totally sh**t the bad but works off and on or partial. maybe that is when when autozone red the code it didn't come up. plus thise may also explain why the 3 dyno runs differ so much and the 2nd run resulted in 149 hp. i have purchased a new knock sensor on e-bay and i am going to do a full tune up when it arrives. throttle body, plugs, pcv valves , coolant flush and whatever else my mechanic decides is needed. thanks for all the help guys.

flashover

a ghost code is one that does not trip the CEL. (CHECK ENGINE LIGHT)

Broaner

iTrader: (10)

If you had an Auterra or similar product you wouldn't have to play the guessing game. I seriously advise that everyone that is going to do performance mods aquires some sort of OBDII reader to help with problems. I was guessing why I was getting such bad mileage for two months. I thought it might be KS related, o2 related, vacum related. When I got the Auterra up and running I immediately eliminated the KS because I was running 23-24 degrees at WOT. Then I read the o2 values and the rear was at 0 constantly. So spending $400 initially on the setup is a lot but it will definitely make up because it will save not buying the wrong parts. I suggest to all enthusiasts to get a reader. That said, you definitely have a wierd dyno. You should start with the basics, as you mentioned like TB clean, Plugs, etc... Don't pay some mechanic to do it. Here is the tool that I have come to love so much already. Already saved me $110.

Zack342

iTrader: (89)

well my original intentions were to get the car a tune up when it got 100K which is pretty close. i already purchased the knock sensor unfortuneately for but it was only $90 shipped on ebay so i will have my mechanic throw that on as well when he is doing the tune up. i am planning purchasing the obd2 scanner as well very sooon. but for not i will just have to go to autozone. i am really hoping that i have a bad knock sensor and that is the root of all the evil but i can only hope. the car still runs excellent and i do notice a slight decline in performance but gas mileage is respectable. i do about 90 miles a day at anywhere from 80-100mph and i get about 350 miles to a tank. i am just going to tune her up and redyno and take it from there .... thanks

Kolyan

anyone agree/experienced with what's said above?

I don't have the code and i did check the knock sensor (measured at 550), but i have the feeling that my car is not pulling hard enough too. all the maintains was done. i figure instead of spending money on dyno, i should spend it on buying a knock sensor.

Broaner

iTrader: (10)

Don't spend money on either. By some sort of OBD-II reader and then it won't be a guessing game and then you'll save more money in the long run.

tweeter007

I checked my ecu last week, it's a 99 and there is a screw, it is very small, white plastic screw, need a precision screwdriver.

Kolyan

Doesn't the reader tell u the same info that u can find out yourself from ECU by turning the screw?

Zack342

iTrader: (89)

i think he mean that i should buy the obd II reader,

Broaner

iTrader: (10)

Yes, it tells you codes x10. Instead of just reading the codes you can read the sensors that are associated with those codes. I was suggesting this to all but Kolyan, it very much applies to you. So, you think your KS is on the verge of dieing but not quite. With a reader you would be able to read live data while driving around. So lets say you hook up the reader and it says your advancing 24 degrees at WOT near redline. That just saved your @ss the $150 for a new KS. Then you look into other areas as to why your lagging and you eventually figure it out without spending a dime. Then you go buy the little part that was causing all the trouble and you've got power back without guessing for several months. Also, yes, the screw works fine for a while but it will eventually break as has mine. Was broken when I got the car.(Presumably by the shady mechanics my mother brought the car to)

Kolyan

the ones with "live data stream" are expensive....

http://www.tradervar.com/store/agora...age=KM9615.htm

or the software readers:

http://www.mp3car.com/vbulletin/show...8&page=1&pp=15

Kolyan

this autotap is pretty interesting....i just don't get if it's just a software that communicates with car, or is there a hardware peice also.....

http://www.autotap.com/products.html

pLoMaXiMuS

just sell the car man... lol joke
nah it hink it is the knock sensor also...

Kenny

Kolyan

I finally got a laptop and learned a bit about this OBD-2 Software. I pasted this from my post in another forum. Can anyone with some knowlage of OBD-2 SW comment here and recommend which one to get.

"Sensors it can read in realtime: http://www.autotap.com/generic_parameters.asp

www.autoenginuity.com --- sensors this one can read realtime:
http://www.autoenginuity.com/sensor_list.html
this software also includes dyno & track results. (don't know how usefull and reliable this is)

and there is another one from http://www.obd2.com, but seems pretty expensive....$275. they say their software monitors ecu every 2 seconds or so for errors (i guess, unlike realtime data, this actually monitor EVERY sensor on the car...maybe i'm wrong) "

96blkonblkse

iTrader: (18)

i thought when the knock sensor went it through ghost codes? dont cali sped cars have more emmissions crap on them

sagamax

iTrader: (5)

i think i am in the same situation you are in. i dynoed 158/176 with my mods and my a/f was about 11.5 so i am running rich. it isnt a knock in my case because i ran the obdII and no codes were pulled i am thinking it is an exhaust leak or my o2 sensors arnt tight enough in. i will hopefully check my o2 sensors this week. i will keep you updated.

sagamax

iTrader: (5)

would that ground strap make a difference i never reinstalled mine also after i installed my y pipe

Zack342

iTrader: (89)

i should mention, i had a tuneup done a couple weeks ago or maybe a month and a half. fuel filter, plugs,knock sensor, coolant flush. car didn't have the knock sensor code but i had my mechanic change it anyway. following this i went to the track car ran a best of 15.1 @93mph with intake/y-pipe/ground kit. car runs fine i will have it redynoed in a week and let you guys know.

ABK

knock sensor is a *****, before mine went out I used to walk my buddies 240 by like 2 cars or more. Now when my knock sensor went to **** he was sitting on my rear and once on my door. 0304 own JO (I think that's the code, don't remember).

Guinader

iTrader: (1)

hey I was at that same maxima dyno meet. (check my cardomain to remember)
my graph has the same looks (not smooth) and I too had a cali spect with a y-pipe and b-pipe.
the difference is I had the engine light on for 1008 canister....
I got 165HP and 177TQ which is just aobnut the same as yours,

well any way, if you find out what is wrong with your car then maybe I will know what is wrong with mine too.

sagamax

iTrader: (5)

just curious what were your a/f #'s and what are some good a/f ratio for a n/a 4th gen

JerzMax

Any updates ???

Maximeltman

iTrader: (11)

I don'y know if this has been corrected, but there is a diagnostic screw on the 99 ecu, next to the gas pedal...unless you are talking about something else.
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Zack342

iTrader: (89)

not sure i just go to autozone and they pull the codes for free. anyway its funny thing old thread should resurface, tomorrow i am actually having the car redynoed hoping for 180whp. since first dyno i have done these things
tune up
Plugs- Correct NGK plats
New Nissan knock Sensor
coolant flush
B&G induction cleaning at nissan.
i have also added a Greddy SP Exhaust
Changed the oil twice. 10W30 Synthetic
and the car now has 103820 miles on it
i will let you guys know tomorrow how it goes. i should add that the knock sensor that was replaced was fine and never threw a code, i just had it done because i bought it and didn't wanna wait until it got bad.
the car runs and drive great only problem is i have notice that the oil pressure sender is leaking a bit of oil which i monitor and will replace when i do the next oil change.