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Check engine light on?

Tiny
TRASHER
  • MEMBER
  • 2001 MITSUBISHI ECLIPSE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 110,000 MILES
My son has a Eclipse GT with a 3.0 V6. The check engine light is on all the time. After having the codes read we were told we had code P1400 with was the "manifold pressure switch".
I pulled it off the manifold and there isn't much to it and re-installed it. The connection was tight and nothing looked wrong as far as the install.
How do you check it out?
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Friday, June 27th, 2008 AT 8:02 PM

44 Replies

Tiny
MASTERTECHTIM
  • MECHANIC
  • 4,750 POSTS
Are you sure its not a egr code. check the vacuum lines to the egr valve to be sure. if you still need help i will research it in the am.

This video will help us fix it

https://youtu.be/vMwTzURWXmk

Please run down this guide and report back.
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Friday, June 27th, 2008 AT 8:37 PM
Tiny
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He went to Autozone and they used their scanner to pull the code P1400. Looking it up it was the
"P1400 Manifold Differential Pressure Sensor Circuit Malfunction (Mitsubishi) "

On some Fords it might be the EGR circuit is what I found

Thank you!
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Friday, June 27th, 2008 AT 9:43 PM
Tiny
MASTERTECHTIM
  • MECHANIC
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You are correct. if you dont have a scanner to watch the pressure voltage of the sensor i would go ahead and replace it due to the most common problem would be a faulty sensor not the computer. let me know


https://www.2carpros.com/forum/automotive_pictures/139033_ac_8.jpg

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Saturday, June 28th, 2008 AT 6:32 AM
Tiny
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I replaced the sensor and it so far has worked. I cleared the codes by disconnecting the battery. Test drove it and turned if off several times. Let's see if this does it. Thanks for your help!
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Saturday, June 28th, 2008 AT 4:56 PM
Tiny
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He has been driving it for two days without a light on so hopefully it's fixed. Going to get the smog check tomorrow so I will know for sure after that :)
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Sunday, June 29th, 2008 AT 9:54 PM
Tiny
MASTERTECHTIM
  • MECHANIC
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Nice
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Monday, June 30th, 2008 AT 7:33 PM
Tiny
BALAJISUBBIAHS
  • MEMBER
  • 2 POSTS
I got the same code for my 2001 Galant LS V6 3.0 L.
EGR is also good.
Can you please let me know the exact part name to change("P1400 Manifold Differential Pressure Sensor Circuit Malfunction (Mitsubishi) ") and approx cost to fix it. Please help. Can we change it or we need labour (mechanic to do it) How much it will cost.

Thanks
Balaji Subbiah S.
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Thursday, July 10th, 2008 AT 10:39 AM
Tiny
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I got the part at Auto Zone since they scanned it for free. It cost $126 :(
It sits on top of your intake manifold and held down with 2 bolts with one electrical connector attached to it
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Saturday, July 12th, 2008 AT 12:21 AM
Tiny
JTODD1122
  • MEMBER
  • 2 POSTS
  • 2001 MITSUBISHI ECLIPSE
  • 4 CYL
  • FWD
  • MANUAL
  • 125,000 MILES
My check engine light has been on, and off, for the past few weeks. It will mysteriously come on, then go away a day or up to a week later. I had someone tell me it was a pressure issue, and I seem to be losing radiator fluid quicker than normal. I thought it might have been because my clutch slave cylinder was leaking, but I fixed that and the light was still on. It just recently went off again, and I was wondering if anyone could offer suggestions. I am not in the market to pay someone hundreds of dollars at this point and could really use some advice. Thanks
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Hi jtodd1122,

Thank you for the donation.

When the CEL indicates, an error has been detected in the engine management or emission system and a trouble code has been recorded in the engine computer.

It can range from a loose/bad gas cap to a faulty engine computer and to understand what could be wrong, you would need to retrieve the trouble code.

Autozone provides free scanning services, get it done and and let me know the exact trouble code so I can get the necessary data.
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
BCKNTOP
  • MEMBER
  • 4 POSTS
  • 2001 MITSUBISHI ECLIPSE
  • 6 CYL
  • FWD
  • MANUAL
  • 100,100 MILES
My car has the error code P1400 I have been quoted 5 hours labor just to find out what the code means. Is there someone that can help me?
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi:
The PO1400 is Manifold Differential Pressure Sensor circuit. What is the car doing?
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
BCKNTOP
  • MEMBER
  • 4 POSTS
It sounds a little hollow, but louder if that makes any sense. I had the radiator replaced about 6 months ago and the check engine ight came n about a week later. I ran over something on the road and it has been on ever Since. I am female and have had various mechanice quote me uppwards of $500.00 just to "Take a look at it" I was told that the P1400 could be alot of different things and it wasn't easy to figure out which it was. Times like this I don't like being single. I would apprecaite any advice you can give me.
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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The code is somewhat generic, and it will require some time to determine what is causing the problem. However, 500 dollars is a bit much. What I suggest is to check around to find someone that is willing to look at it for as little as possible.

You described it as having a hollow sound. Have you checked to make sure the air filter box and intake tube is properly attached? Also, when you hit something on the road, could it have damaged the exhaust?

Joe
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
BCKNTOP
  • MEMBER
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Hi Joe,
I have had friends look at it and was told everything looks fine. The Mechanic that gave me the code yesterday checked the hoses and the air filter and said it all looks good. He told me to go on this site and find out what the problem area was and if it isn't something difficult, he would do the repair, but again, he doesn't like to work on Eclipse's due to the way it is put together. If it is the Manifold Differential Pressure Sensor circuit, what would the Symptoms be? The car sounds like there might be something wrong with the exhaust system. No one I know will touch my car due to the fact that everything is so hard to get to. They don't want to deal with it. The problem is I still need to get it fixed as inexpensively as possible.
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
GAB4ISO
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  • 2001 MITSUBISHI ECLIPSE
  • 4 CYL
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  • AUTOMATIC
  • 97,000 MILES
I just bought this car for my 16 year old son. On the way home the "Service Engine Soon" light went on. What does that mean?
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
BLACKOP555
  • MECHANIC
  • 10,371 POSTS
It means that there is somethign wrong with the vehicle that the pcm has picked up.

Besat thing to do is have it scanned and see what is wrong with it, it will tell you whats wrong!

Take it to autozone for a free check, some auto values will do it also.

Or you can go to just about any mechanic and pay to have it done.
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi:
Believe me, I understand. Based on the code, I would believe there is a vacuum leak somewhere on or around the intake. It could cause a noise that you described. Also, check the exhaust for leaks. On this type of car I'm concerned that a change in backpressure may even set the code.
Also, the Manifold Differential Pressure switch (MDP) sits on top of your intake manifold and monitors the air pressure. Check it to see if it's mounted good and maybe unplug it and plug it back in to see if there may be corrosion on the plug. Also, have someone check closely for leaks there, remove the MDP and clean it if carboned up and properly replace it. The more I think of it, the more I think that is where the problem is. You may also want to have the EGR checked for leaks, if it's stuck, or carboned up too.

Let me know what you find, or if you have other questions.

Joe
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
BCKNTOP
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Thank you, I will keep you informed. I appreciate all your suggestions!
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)
Tiny
TONYYANKEE
  • MEMBER
  • 1 POST
  • 2001 MITSUBISHI ECLIPSE
  • 6 CYL
  • AWD
  • AUTOMATIC
  • 130,000 MILES
The service engine light turn on and a couple of days prior I had taken it for an oil change in which they check everything. What could be the cause of it.

Updated 7/29/09
thank you for your help I am really thankfull. After carefully checking the engine and making sure everything was good found out that the air filter was not installed correctly after a while the light turned off and everything is running good. Once again thank you for your help.
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Monday, August 3rd, 2020 AT 2:49 PM (Merged)

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