So a few months ago I got a P0401 and did a lot of reading on mud and the FSM in an attempt to get things lined up for taking care of the problem. I am a poor mechanic but want to learn so figured I'd give tackling this problem a try.
I had a week to get it done (it shouldn't take that long) and didn't have time to do as much diagnosis/trouble shooting as I would have liked but was pretty certain my EGR regulator and valve were ok. I wasn't sure about the VSV and decided to replace it as well as the other components as they weren't looking great. I just didn't want to have to come back and do things over.
I'm posting this thread, not as a way to diagnose what is wrong, but more as a thread to show what I did with lots of pictures in the attempt that anyone else running into this problem will have some pictures as references. If I describe anything wrong or lable anything wrong please PM me so that I can fix it for other people's sake. I am just hoping to contribute back a little for all that you guys have done for me. So here goes....
Heres a list of links I found helpful in doing this project.
https://forum.ih8mud.com/80-series-tech/540650-throttle-body-baseline.html
https://forum.ih8mud.com/80-series-tech/65702-code-p0401.html
https://forum.ih8mud.com/80-series-tech/363575-p0401-defeated-pics.html
https://forum.ih8mud.com/80-series-tech/203948-replacement-vsv-spanish.html
https://forum.ih8mud.com/80-series-tech/295289-9-times-out-10-po401-code-fixed.html
Here is a link that seems like an easy way to test the VSV for EGR and moving it from under the manifold. I hadn't seen this post when I had started working on mine. I may move it later if I ever have to go back in there.
https://forum.ih8mud.com/threads/checking-vsv-for-egr-easy-way-p0401.211364/
Here's a list of the parts I ordered from Cdan (I did the PHH and a coolant flush per e9999 thread as well during this project):
EGR system:
EGR Vacuum Modulator (Blue top)
VSV for EGR
EGR valve
EGR valve stud bolts and nuts that go into the air intake chamber x2 (mine were slightly stripped from a previous dissasembly with the wrong tools)
Vacuum hose
EGR gasket
Air intake gasket x2
PHH:
Gates greenstripe
Fuel injector cleaning:
Upper O ring and rubber grommet x6 (comes with cleaning service)
Lower seal on intake manifold side (fuel injector insulator) x6 (came with cleaning service from RC engineering but not others that I spoke with).
Gaskets for banjo bolt (union bolt) on Fuel Rail x2
Other maintnence:
Gas Cap
Air filter
Gas filter with 4 gaskets for the union bolts (came with filter)
PCV valve and grommet and hoses
First a little overview of car anatomy. In the first picture.
1. EGR Vacuum modulator
2. EGR valve
3. EGR gas temperature sensor
4. Brake booster vacuum hose
5. ?
6. Throttle body position sensor
7. Fuel pressure regulator
8. PCV valve and PCV hose #1
9. PCV hose #2
In picture #2.
1. Throttle body
2. Upper air intake manifold.
I had a week to get it done (it shouldn't take that long) and didn't have time to do as much diagnosis/trouble shooting as I would have liked but was pretty certain my EGR regulator and valve were ok. I wasn't sure about the VSV and decided to replace it as well as the other components as they weren't looking great. I just didn't want to have to come back and do things over.
I'm posting this thread, not as a way to diagnose what is wrong, but more as a thread to show what I did with lots of pictures in the attempt that anyone else running into this problem will have some pictures as references. If I describe anything wrong or lable anything wrong please PM me so that I can fix it for other people's sake. I am just hoping to contribute back a little for all that you guys have done for me. So here goes....
Heres a list of links I found helpful in doing this project.
https://forum.ih8mud.com/80-series-tech/540650-throttle-body-baseline.html
https://forum.ih8mud.com/80-series-tech/65702-code-p0401.html
https://forum.ih8mud.com/80-series-tech/363575-p0401-defeated-pics.html
https://forum.ih8mud.com/80-series-tech/203948-replacement-vsv-spanish.html
https://forum.ih8mud.com/80-series-tech/295289-9-times-out-10-po401-code-fixed.html
Here is a link that seems like an easy way to test the VSV for EGR and moving it from under the manifold. I hadn't seen this post when I had started working on mine. I may move it later if I ever have to go back in there.
https://forum.ih8mud.com/threads/checking-vsv-for-egr-easy-way-p0401.211364/
Here's a list of the parts I ordered from Cdan (I did the PHH and a coolant flush per e9999 thread as well during this project):
EGR system:
EGR Vacuum Modulator (Blue top)
VSV for EGR
EGR valve
EGR valve stud bolts and nuts that go into the air intake chamber x2 (mine were slightly stripped from a previous dissasembly with the wrong tools)
Vacuum hose
EGR gasket
Air intake gasket x2
PHH:
Gates greenstripe
Fuel injector cleaning:
Upper O ring and rubber grommet x6 (comes with cleaning service)
Lower seal on intake manifold side (fuel injector insulator) x6 (came with cleaning service from RC engineering but not others that I spoke with).
Gaskets for banjo bolt (union bolt) on Fuel Rail x2
Other maintnence:
Gas Cap
Air filter
Gas filter with 4 gaskets for the union bolts (came with filter)
PCV valve and grommet and hoses
First a little overview of car anatomy. In the first picture.
1. EGR Vacuum modulator
2. EGR valve
3. EGR gas temperature sensor
4. Brake booster vacuum hose
5. ?
6. Throttle body position sensor
7. Fuel pressure regulator
8. PCV valve and PCV hose #1
9. PCV hose #2
In picture #2.
1. Throttle body
2. Upper air intake manifold.
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