hi all
i dyno my car tody my air/fuel 17 am so sad coz its very lean its give 254hp and 245tq ,my car have full boltons ,my mods : Greddy evo2,hlix test pipe ,topspeed headers ,cia injen ,ur pulley,crawfordz Plenum,some one tell me i lose 30rwhp with this lean and maby i have some sensor not work??!! ,in the street when i race with my brother altima 3.5 his car mods Greddy evo2 and AEM cia ,in the gear 1 to 3 the altima go ,i race some stock z i go about 1 to 2 cars whay ?
what can i do with my air/fuel ?

 

1) Get engine management or a reflash

2) Get a tune on a load based dyno

 

17 AFR is extremely dangerous level!! stop driving your car and get a tune ASAP.

post the dyno graph if possible.

 

sounds to me like the MAF is dead or very close. Nissans MAF sensors like to go lean as they get old. which your seems to be in a bad way. at 17 i dont think the car would get with a crap. Either u have a intake leak or the MAF is bad. you have to much air like a intake leak. have someone that knows something about it check it out.

 

Somehow I doubt the engine can even get up to 17 AFR on N/A mods (especially without throwing any codes or going into limp mode...). This could simply be an inaccurate measurement.

Was it 17 AFR throughout the entire RPM band? What was the range, lowest to highest?

 

tune your car ASAP

 

I agree. I dont think this was recorded with a wideband. It was probably with a sniffer tool stuffed in the exhaust. We all know those can be inaccurate. With a a/f ratio of 17 check engine has to turn on, the knock sensor would have to record knock, and the ecu has to retard timing if it doesnt then you have bigger fish to fry.

 

see this dyno before 3 month install the crawfordz Plenum and the headers ,
this 2 dyno i make it yesterday ,i remember now the check engine light turn ON about 3 days and it go after


i think the car have problem i dont feel fast ??!!

 

+1 on MAF.
I had my Popcharger oil get on my MAF and that
leaned the crap out of my A/F ratio.
First check the MAF. If that's not causing the problem,
time for ECU reflash. With full bold-ons, especially with headers,
you need to reflash your ECU anyway.

 

this good HP Tq ? with full boltons?
are the MAF altima 3.5 work with the Z to try it ?

 

get the check engine light checked out first i bet it has a P0171 fuel system lean bank 1 or P0172 bank 2. i bet the air fuel alpha is at 125%

 

how can i check it ?

 

If your mass air flow sensor is dead you would not be able to even dyno. The car would not rev past 3000 if that was the fact. I feel the mass air flow sensor could be dirty, or have a connection problem. If it was dead the tcs light and cel light would be on all the time also.


If you want to check what your check engine light is showing get a OBD scanner for like $50 bucks.

 

This could easily be an air leak after the MAF sensor. I noticed that you had a plenum installed. This could result in unmetered air getting in if installed incorrectly. If you register a certain amount of air, and then allow more to enter without being metered, the ratio will lean out (stated above by someone else). If the MAF wasn't working, or producing unrealiable results the computer would ignore the input and rely on other sensors to determine ratio. The first thing I would check is the install of the plenum, tightess of the bolts, etc... Good luck!

 

i check the air leake today i didnt find any leak am so sad ): i can`t drive my car with tis lean .i will try to clean my MAF.

 

u cant clean the MAF there is no adjustment on it either. YOU WILL DESTROY IT!!! you have to find someone with a OBD II scanner and see what codes there is and see how its running. I dont think you know what your doing when u checked for intake leaks. U cant see them and you have to be looking at the sensor readings while checking them. plz take it to someone who knows what they are doing.

 

You can clean the maf sensor. You need to buy maf cleaner though. The only way you would blow it with the correct cleaner; is if you put it back together wet.

Sincerely Glen

 

i used quick drying electrical contact cleaner on my maf when i got oil on it

 

i will go to the nissan company tomorrow to check me car , and i redy to order the Greddy e-manage ultimate to tune my car am so sad

 

You can check for intake leaks by spraying ether (starting fluid) around the plenum and listening to the idle. If the idle goes up while spraying, it means the fluid is getting into the air stream, and you have a leak. This is a crude method, but usually very effective to check for installation probs.