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Jake, Nissan Technician
Category: Nissan
Satisfied Customers: 4001
Experience:  Experienced collision repair technician, Pulaski Tech graduate and DSM hobbyist.
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Jay, I am having a issue with a 2004 nissan quest that I

Customer Question

Hey Jay, I am having a issue with a 2004 nissan quest that I recently purchased a month ago. The van misfires at low speed with a rough idle. So far I replaced the rear catalytic converter near the firewall since the original didn't have the honey comb. Replaced all new spark plugs and ignition coils ( all dealer parts ). The exhaust system had a few cracks in between but everything was welded. The check engine light is on with a code for bank2 sensor1, waiting to replace.I want ti know if i replace the sensor will it solve the problem or will this van become a fat cat that cant perform. Went to a few mechanics but no one is able to detect the main problem.
Submitted: 1 year ago.
Category: Nissan
Expert:  Jake replied 1 year ago.
Hey there, since Jay is not online now I will be happy to help in the meantime.If you have an issue with bank 2 sensor 1 it will need to replaced in order to get the fuel trims corrected. Fuel trim issue will cause misfiring, bogging, poor idle issues. So you need to start their.If the misfire continues afterwards for some reason then let me know details like if it only misses at idle or it also misses under acceleration.
Customer: replied 1 year ago.
I have replaced the sensor for bank 2 sensor 1 and the van still misfires when accelerating. When the van is idling it idles rough, the rpm needle goes up and down between 0800-1900 rpm. Notice the service engine light is blinking more often now since the sensor was replaced. Any ideas what could be the next problem?
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Jake replied 1 year ago.

I have some good ideas of what may be going on.

Do you own the code reader you used to pull codes? if so, does it have an option to view live data when the engine is running?

Customer: replied 1 year ago.
Good morning, I don't own the code reader. I was able to have auto zone put their computer on the van. It showed mutiple misfires.
Expert:  Jake replied 1 year ago.

Thanks, ***** ***** concerned with live data because your symptoms could be from an intake leak at bank 2. This would cause bad idle and multiple cylinder misfires. Since you had an O2 sensor code for that bank as well, the lean readings might have triggered that as well.

Since you don't have a way to read live data and verify. Start by spraying some carb cleaner or something of that nature at the intake gaskets. Look for the idle to smooth or change when you find the leak. Also listed for an obvious hissing.

Customer: replied 1 year ago.
I cleaned the intake throttle, the area where the air intake is located. The van continues to idle rough. I don't hear any hissing noise from any part of the exhaust system, even if I rev the engine. This van is becoming a guessing game.
Expert:  Jake replied 1 year ago.

The hissing your listening for would be under the hood on the intake manifold area, not the exhaust.

Expert:  Jake replied 1 year ago.

im not too concerned with the throttle, its the intake manifold gaskets leaking that is my concern. You need to smoke the intake or use carb cleaner to spray around the manifold gasket with the engine running to look for the leak.

Customer: replied 1 year ago.
What product do you recommend to smoke the intake?
About three weeks back the van was inspected by a shop and they said the engine was sealed. They couldn't find any air leaks. One thing they noted was the exhaust was choking, not enough air flow. I checked the rear exhaust manifold ( the manifold past the fire wall ) for any blockage but nothing was discovered.
In your years of experience do you think a faulty manifold gasket will cause the misfire and rough idle?
Expert:  Jake replied 1 year ago.
Manifold leaks and gasket leaks will trigger o2 and lean codes all day but rarely cause a misfire and when they do it's more like a hiccup, not what your seeing.
Expert:  Jake replied 1 year ago.
This year model did have some injector harness issues, but I really wish I could see your fuel trims for peace of mind on an air leak or MAF issue.