I am in process of changing oxygen sensors on my 2006 Grand Cherokee. It's a Laredo 4x4 with the 3.7L engine and NAG1 transmission.

The two downstream sensors are a piece of cake to change out and they're done. The driver's side upstream sensor was difficult to unplug. I found that removing the wheel well gives better access. I have changed this sensor.

The passenger side upstream sensor is almost impossible. The engineers, in their infinite wisdom, decided to wedge the O2 connector in between the transmission bell housing and the transmission dipstick tube. it looks like the tube will need to be removed to get access to the plug.

To remove the dipstick tube there are two bolts. One is at the base of the transmission where the tube and seal are located. The other is one of the bell housing bolts that supports the tube. I can't figure out how the heck to unbolt the bell housing bolt, given the angle and the amount of room to turn a wrench. I would try unbolting it through the passenger wheel well but, conveniently, there is a small shroud covering the bolt from the side I am trying to loosen it from.

Has anyone else had experience changing these sensors on this model vehicle, or at least removing the dipstick tube?

 

I just found your post from 5 years ago as I am running into the same issue. I'm not even sure that the 02 sensors are what is causing my problem, but I've eliminated/replaced plugs, coil packs, and fuel issues and still getting a "random misfire" unspecified. That being said, I've decided to replace all four sensors in hopes that those are where my problem lies.

How did you end up accessing the "problem sensor"?

Thanks,

Ronny

 

Hi, Alec. Welcome to the forum.

Bad news - that post above was his last post. I don't think he's going to answer you. Here's a quick tip - If you right-click on a username, you can go to their profile, and there you'll see their last post listed. It can be helpful when looking up old threads.

I wish I could help you on your question. I don't have a V8 Grand, so I'm not much good to you. But maybe someone else will come along to assist.

Have you tried YouTube?

 

I never figured it out and took it to a local mechanic. They fixed it. No clue how they got up in there.

 

Gerbils. They have trained gerbils. It's a well-kept secret!



Thanks for coming back to respond! That doesn't happen very often!

 

Hey Alec found your reply on a post from 3 years ago hopefully you respond haha. I seen you have a misfiring problem I was wondering if you got that fixed and if so what was the cause