# 99 Altima - Cylinder #4 Misfire + System too Lean bank 1



## l337hxr (May 12, 2006)

Okay my sister's 1999 altima GXE has 90K miles on it. Its an auto. Basically it is throwing a CEL but the car drives ok. It idles a little bit rough. Anyways, I ran the codes, and thats what it tells me:

Cylinder #4 Misfire
System Too Lean Bank 1


She took the car to ashop and they told her, that her 'exhaust' is leaking and when they lift the car up, they can see where the leak is. I assume the part they are talking now is possibly the 'FLEX Pipe' ??? are flex pipes on 99 altimas notoriously known to crack? but i figured thats where its broken..i haven't looked under the car yet to be 100% but when I do, i'm going to order her the $85 Bosal flexpipe replacement...that should be good enough right?

I know that when I idle the car, and I pop her hood and stand in front of the car, I can smell gasoline... I suspect this is the exhaust leak from the unburnt fuel...leaking out before the catalytic converter... hence, why i'm thinking it has to be the flexpipe right?

As for her misfire, i believe her spark plugs are probably gone... the car drives fine under normal conditions...it just idles a little funny... so i think the distributer should be ok....other than that... what are your thoughts guys?

thanks!


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## LONDONDERRY (May 19, 2004)

l337hxr said:


> Okay my sister's 1999 altima GXE has 90K miles on it. Its an auto. Basically it is throwing a CEL but the car drives ok. It idles a little bit rough. Anyways, I ran the codes, and thats what it tells me:
> 
> Cylinder #4 Misfire
> System Too Lean Bank 1
> ...


See if the Intake gasket is leaking


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## l337hxr (May 12, 2006)

LONDONDERRY said:


> See if the Intake gasket is leaking


ok i just did a quick and dirty tune up... replaced the air filter, fuel filter, and four spark plugs and gapped them correctly. It still seems to idle a little wierd.

Other than that, when I pulled the left-most spark plug (facing the front of car), i noticed this spark plug had a LOT of oil on it... could this be cylinder #4 and why its mis-firing?

somebody school me..thanks


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## Darktide (Jul 29, 2004)

Sorry to tell you but Londonderry was correct in the fact that it sounds like you blew your intake gasket. And the oil basically confirms it. I've never had to do the job myself so I'm not sure how long it takes but if you do a search you'll have already found PLENTY of information on the intake gasket problem. Best of luck to you.

Darktide


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## AltimaBlues (Apr 6, 2006)

l337hxr said:


> ok i just did a quick and dirty tune up... replaced the air filter, fuel filter, and four spark plugs and gapped them correctly. It still seems to idle a little wierd.
> 
> Other than that, when I pulled the left-most spark plug (facing the front of car), i noticed this spark plug had a LOT of oil on it... could this be cylinder #4 and why its mis-firing?
> 
> somebody school me..thanks


If the oil was on the upper part of the spark plug, in the well where the wire connects, then you have a leak in the rubber seals inside the valve cover. It was an easy repair for me on my 98 Altima. I got a error code that that particular cylinder was misfiring.


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## topgear (Jul 24, 2006)

I've got the same problem  



> 1999 altima GXE has 90K miles on it. Its an auto. Basically it is throwing a CEL but the car drives ok. It idles a little bit rough. Anyways, I ran the codes, and thats what it tells me:
> 
> Cylinder #4 Misfire
> System Too Lean Bank 1


Do you recommend taking it to a dealer or a local shop and ask them to check the intake manifold gasket?

How much would something like this run?

Thank you

Topgear


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## LONDONDERRY (May 19, 2004)

topgear said:


> I've got the same problem
> 
> 
> 
> ...


Don't do either unless your unfamilar with your car. Buy some air intake cleaner, with the car running, spray around the intake manifold, if it quiets down you know you have a leak. In addtion, if the engine light is on, Autozone with scan it for free. I suggest you look at a haynes manual to read up on the code. However, if you want to have your car serviced, any local mechanic can handle this task with confidence.

Frank


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## ntanenbaum (Jun 25, 2006)

It's the intake manifold gasket causing this issue. A way to check if it's the Intake Manifold Gasket is to spray carb cleaner inbetween the intake and head of the engine where it connects while running and see if the idle smooths out for a few seconds enough for the carb cleaner to fill the gap where it leaking. My experience is that the design of the engine/intake is very poor being that the EGR pipe runs right next to cylinder 4 and it bakes the intake manifold gasket. This is very common issue on these cars.....I am having the same issue and getting it fix for about $470 for a local mechanic. Recommend NOT to go to the dealer they will charge an arm and a leg ($825 I was quoted). I have a 2000 GXE with 57,000 miles on it.


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