I am getting MAP and EGR codes on my son's 04 S with the 4.2. They come back rapidly after clearing and I know they are often related so I decided to start with the MAP sensor replacement.

I have done a number of searches and other than finding out it's a pain on the 4.2, there does not seem to be any specific instructions on how to do it. I know it's at the back of the engine and we have removed the plastic cowling and the cross brace to get access to the rear of the engine, but I still can't see the sensor.
The main wiring harness crosses the back of the engine and I assume I need to move that aside.
Any other pointers or steps to gain access?

Thanks,
John

 

Which codes?

Maybe an air leak under certain circumstances so look at the freeze frame data and ponder.

 

My quality Bluetooth reader decided to pack it in, but my basic reader shows PO105 (MAP sensor) and PO400 (EGR Flow). The car has 220,000 KM's on it. The car still runs OK but he is reporting some minor surging is now occurring.
Since I have the MAP sensor in hand, I would like to get it installed and then dig into the EGR if I have too.
I read somewhere that the intake manifold needs to come out to get at the MAP sensor. Is that correct?
Thanks,
John

 

If you have access to the Service manual, check the procedure for removal of the Intake Manifold---there is a reasonable illustration there showing the location of the MAP sensor and it is under the engine harness support bracket at the rear.

If you do not have a Manual,PM me your email address and I will send you a zip file, or If you are in the east end I could loan you my CD.

 

Odd for 2 codes to come up at once unless there's a common cause - chafed wire maybe? Water?

Often recent work is the cause.

 

Thanks for the responses.

I think the codes have come up over a period of time, and we just didn't have the time to look into it. Unfortunately I can't remember which one appeared first.

So I removed the harness bracket and with just the small amount of movement I can get with the large harness, I can see the sensor. It looks like there is room to get at it, with the harness fully removed. That looks to be a chore on its own as the harness is pretty stiff and brittle, but if that is the method I will go at it. I just want to make sure the manifold does not have to come off as I would want to have the gasket on hand before tackling the manifold removal.

So can we confirm that the manifold does not need to come off.
John

 

Well, I decided to give it a try and was successful.

I removed the harness bracket at the rear of the engine, then on the left side of the engine I removed the injector and coil connections which allowed the harness to move up enough to get my hand in the back and working with a small 1/4 drive torx bit I was able to remove the 2 screws and extract the sensor.

It's tight and you will have a few cuts and scrapes at the end but it is doable. I would have liked to completely remove the harness, but I could not figure out how to separate the electrical connectors that have the little red slide on them. I can slide the red bar to the unlock position, but there is clearly another step since they would still not come apart. Any help on these connectors would be appreciated as these will need to come apart if I have to do the intake gasket.

I have now cleared the codes and we will see what comes back.

John

 

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Hi, I saw your comment here and I have a 2004 XJ8 with a MAP sensor problem.
I'm living on the east side of Toronto and I would appreciate you would send me a zip file with the procedure to replace the sensor.
My email is marmar1305@yahoo.com
Thanks Marc

 

Wrong forum and anyway you can probably just download the manual.