Front Exhaust Tube Questions

[SailingAltima]

I'm looking to replace the front exhaust tube on my 2008 2.5S sedan and have a couple of questions.

1. It looks like there are two O2 sensors on the car, one on the exhaust manifold and one at the front end of the front exhaust tube. On my front exhaust tube I have a sensor of some sort at the back end of the tube as well as the front. Is this a third O2 sensor? If not, what is it?

2. Looking at the studs that mount the exhaust tube onto the exhaust manifold and I'm pretty confident that I will destroy them if I try to take them apart. Are those studs available by themselves or do I have to get them with the exhaust manifold?

3. I'm trying to find part numbers for all these parts and am coming up empty. Is there a diagram with part numbers so I know what I'm asking for?

4. How essential is it to get CARB compliant parts if I'm not in CA or NY? I highly doubt that I'll be driving to CA but I can see myself driving through NY.

[OwnerCS]

I'm looking to replace the front exhaust tube on my 2008 2.5S sedan and have a couple of questions.

1. It looks like there are two O2 sensors on the car, one on the exhaust manifold and one at the front end of the front exhaust tube. On my front exhaust tube I have a sensor of some sort at the back end of the tube as well as the front. Is this a third O2 sensor? If not, what is it?

2. Looking at the studs that mount the exhaust tube onto the exhaust manifold and I'm pretty confident that I will destroy them if I try to take them apart. Are those studs available by themselves or do I have to get them with the exhaust manifold?

3. I'm trying to find part numbers for all these parts and am coming up empty. Is there a diagram with part numbers so I know what I'm asking for?

4. How essential is it to get CARB compliant parts if I'm not in CA or NY? I highly doubt that I'll be driving to CA but I can see myself driving through NY.

I'm not an 08 Altima expert, but I will try to answer your questions the best that I can.

Questions:

1. There are three O2 sensors shown for an 08 Maxima.

cyl head ---> sensor #1 ---> cat #1 ---> sensor #2 ---> cat #2 ---> sensor #3 ----> tailpipe

2. and 3. The exhaust studs can be purchased from a Dealer Site or from some online retailers that specialize in Nissans. I believe Nissan exhaust studs are a fairly common item across many models. The Nissan part number is: 14064WF701

This link should take you to the diagram page where the part number is listed. Also, parts stores like O"Reilly Auto and Advance auto should be selling a Dorman replacement part for your Altima. You can also buy replacement nuts there as well. Use nuts that are suited for a high heat application -- not the decorative chrome plated type.

I usually soak my exhaust bolts with a penetrating lubricant like PBlaster the night before I remove them.

Parts Diagram

https://www.nissanpartsdeal.com/parts/n ... wf701.html

I've found that removing difficult exhaust system nuts can be helped by using an impact type universal joint. I use this when I cannot get a straight line from my 1/2 inch ratchet extension to the exhaust bolt. The way this type of u-joint is made allows torque to be evenly applied during removal. The common wobble type u-joints do work in some instances. However, someone may hit places during turning where the joint locks and does not evenly distribute torque to the nut or bolt that is being removed.



4. Depends on where you live and your state's inspection requirements. There are states that perform exhaust system checks as part of the vehicle inspection process. In my state there are no inspections. So I have owned vehicles without cats or I have installed y-pipes that bypass the precats. If you meet your state's vehicle inspection requirements, you will be licensed in that state and entitled to travel through and visit other states.