# 1998 Altima SE, p0171 code misfire



## Hamed (May 7, 2009)

Hi,

I'm a new member here and also new to Nissan,
I just recently bought a 1998 Altima SE Auto with 120K miles.

The cars seems to run fine, but SES light is on with code p0171 (system lean)
At a stop I do have vIbrations,
If I put the car in drive and ac on, (car warm when cold no problem)
the idle changes between 500 and 700 rpm is this normal?? or should it be steady all the time?

and I do have vibrations,
Its not too bad but noticeable, (I do have bad engine mounts too :d that might be the case 

If I put it in neutral the idle will be steady and idle at 750 rpm.

BUT last night I was driving and had really bad misfires even the SES light started blinking at some times,

I changed the spark plugs and air filter (both were very bad) now the car is running fine or at least same as before.

Will the car be fine or will the misfire come back?? can that happen?
Can this be the famous intake manifold gasket leak? or is it other things?

any suggestions what should I look for?
Thanks


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## Kraut-n-Rice (Jan 10, 2007)

Hamed said:


> Hi,
> 
> I'm a new member here and also new to Nissan,
> I just recently bought a 1998 Altima SE Auto with 120K miles.
> ...


Do a search for " intake gasket " you will find that much of what you have are the exact symptoms , it is very common and ceratin to happen. Buy Felpro brand gasket , they are an improved material over the OE and resist heat better. The Felpro kit includes the collector gasket and intake gasket . Buy the throttle body gasket , pcv valve ,fuel filter and EGR gasket as well . You might as well do all of those while you are in the area and have things apart. Shouldn't be more than $60 for all those parts.


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## CMax03 (Jan 17, 2009)

I didn't even use the plenum to runner gasket, just the intake manifold to head gasket! Take the front and rear motor mounts/ cross member off and you'll have enough room to remove the entire intake manifold by moving the engine around!


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