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Jay
Jay, Nissan Technician
Category: Nissan
Satisfied Customers: 18879
Experience:  20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer
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2002 nissan altima: SL..light throttle..idling..It also stumbles

Resolved Question:

I have a 2002 nissan altima 2.5 SL and it has stumbling during light throttle and idling. It also stumbles while driving.
I replaced the spark plugs and put a set of BWD ignition coils but I still hav the same problem.What can I do to solve this?
The consumer guide has it under Engine Stalling and that a resistor needs to be installed between the coil and the spark plugs.What is the name of the resistor and where do I get it?
Submitted: 7 years ago.
Category: Nissan
Expert:  Jay replied 7 years ago.
Hello and thank you for using JustAnswer.com

Do you have a service engine soon light on?

Let me know, thanks Jay!
Customer: replied 7 years ago.
No I dont have a service engine soon light on.
Expert:  Jay replied 7 years ago.
Do you have acess to a scanner?

Let me know, Thanks Jay!
Customer: replied 7 years ago.
Not immediately but I can tomorrow and get back to you.
Expert:  Jay replied 7 years ago.
That would be fine. I am off from work tomorrow and will be on most of the day and all of the evening. I would like you to check the air and fuel mixture and let me know what it's reading.

I will talk to you tomorrow. Thanks Jay!
Customer: replied 7 years ago.

I got a scanner and plugged it up to the car and got a P0420 code (catalytic converter).

Could this be my problem and do I need to change the oxygen sensors too?

Expert:  Jay replied 7 years ago.
How many miles do you have on your car?

Let me know, Thanks Jay!
Customer: replied 7 years ago.
I have 168,000 miles and I just recondition the cylinder head due to a blown head gasket.
Expert:  Jay replied 7 years ago.
Oh man! I hate to say it. The Catt Converter has failed. That is your first problem with the service engine soon light. It's not a 02 sensor problem. When these catt converters fail, they break up towards the top, and because of this the debris gets sucked into the engine contaminating the entire engine. Once the engine is contaminated, there is no point in trying to repair it. The contamination will only come back and cause issues. The most common that is the first thing it does is burn oil. If you just had a head gasket done and you are having these issues, I would take it back to the mechanic who did the work. You paid to have your car fixed and it sounds like he went about it the wrong way. The stumbling could be due to the work that was performed.

At this point, if you have a oil consumption problem, then most likely your motor is contaminated and will only get worse. But if you don't, then replace that Catt ASAP before it does any damage to your engine.

If you have any more questions on this, please feel free to ask. Thanks Jay!
Customer: replied 7 years ago.

There is no service soon engine light and i am not burning oil.The car runs fine it just stumbles or you may call it miss fire when I throttle slightly over 1,000 rpm and slightly at idle, otherwise it runs fine.If I throttle from take off straight to 1,300 rpm all is ok.

Just to let you know I bought the car 4weeks ago from someone with the head gasket blown, they sold it to me as is.I did the work step by step with the tools specified.The cylinder head was reconditioned by a well known place called Dover cylynder heads in Atlanta Georgia.

When I got the car going a lot of antifreeze was still in the exhaust so I had to run it for a long time.

Expert:  Jay replied 7 years ago.
Well before you do any damage to this engine, I would get that catt converter changed ASAP.

What make spark plugs did you install?

Let me know, thanks Jay!
Customer: replied 7 years ago.

I installed NGK laser Platinum Iridium as recomended.

I will replace the cat by friday.

Expert:  Jay replied 7 years ago.
Do you still have the scanner? I was wondering if you can check the air and fuel mixture for me.

Let me know, thanks Jay!
Customer: replied 7 years ago.

My friend owns the scanner so I will have to drop by his house again tomorrow>

Just to let you know that I pulled up consumerGuide automotive and their study shows this as a trouble spot for this car.

The article states-ENGINE STALLING:a problem with the ignition coils causes stumbling during light throttle cruise or stalling at idle,requiring installation of a resistor between the coils and spark plugs.(2002)What resistor are they talking about?

I am only having the stumbling during light throttle not the stalling at Idle.

I will scan it tomorrow checking the air and fuel mixture.

Expert:  Jay replied 7 years ago.
When the car is fully warmed up, what does it idle at ? not in gear?

The resistor is built into the coils. I know you put after market coils in the car, that could be causing your problem as well.

My question is did you ever perform a Idle relearn after you had the work done to the car? Where is your idle at when the car is fully warmed up?

Let me know, thanks Jay!
Customer: replied 7 years ago.

Yes I had a shop that specialize in nissan with a new machine relearn the idle and it is idling at about 700 -750rpm in park.

I took back the aftermarket coils because I got the same problem with them as the old ones.Are you saying what I was thinking in the first place ,is to go get the OEM from the dealer?The coils on it are the originals and they did get overheated when the previous owner blew the head gasket.

So them lets sum it up ,the new dealer coils are now improved with the resistor to correct this problem.

I saw a lot of blog about this same problem on the internet.

Before I buy any thing more I will get the coils checked then go from there.

Thanks.

Expert:  Jay replied 7 years ago.
Great! Glad you got the idle relearn done. Since you mentioned you had all that work done I was wondering about that.

As for your coils, I can tell you right now, when it comes to electrical parts, the dealer is the only way to go. After market electical parts never seem to work on the newer Nissans. So I would start with coils.

Thanks Jay!
Jay and 5 other Nissan Specialists are ready to help you
Customer: replied 7 years ago.

I will get back to you tomorrow after I have the coils checked and then replaced.

I will let you know the outcome the we can close.

Expert:  Jay replied 7 years ago.
Not a problem. Talk to you tomorrow evening. I am normally on after 7 pm EST. I may be on and off through out the day, depending if work is slow or not.

Thanks Jay!
Customer: replied 7 years ago.

Hi lay,

I finally got the nissan oem ignition coil and the problem is gone.

thank you.