check engine light -- P1400 code
 

Help!
My wife just got a 2001 eclipse spyder 3.0 V6 -- put regular gas in it.
I added octane booster but it was too late she ran half a tank through it.
The engine light came on with a p1400 emissions code. probably from insufficiant octane for the firing.
It has premium in it now and the octane boost so it should be running at least 94 octane.
The check engine light came on again. I did not get a chance to check it at Autozone but I can only imagine that it is the same code.
Any suggestions? Is there something that gets gummed up because of the shortage of octane that I should replace?
THanks,

RE: check engine light -- P1400 code
 

i dont know if that is because of insufficient octane. I am not totally sure but what i found on the web says that it is this

P1400: Manifold Differential Pressure Sensor circuit.

RE: check engine light -- P1400 code
 

and then...?

Does that suggest that there is a loose bolt on the manifold?... leaking manifold?
The guy at AutoZone said it was an emissions code.

RE: check engine light -- P1400 code
 

i am really not sure what that is i just know that is what the code is saying. The thing with what the guy said at autozone is that he really doesnt have a good manual to tell you what the problem really is cuz all he has is a code book. But with the OBD II reader any code that does not start with a zero is going to be specific to the car manufacuturer. And when i looked up mitsubishi for that code. This was what i came up with. Once again i have no idea what that could mean. Hopefully someone else on here can help you with that

RE: check engine light -- P1400 code
 

P 1400 manifold differential pressior sensor or mdp, replace mdp sensor part # MD305600 list price at 157.06 plus 1.5 labor time. go to your nearest dealer and let them deal with it. And that does not relate to exhaust manifold leak...trust me [8D]

RE: check engine light -- P1400 code
 

Is this normal for a little sensor to go out on a 5 year old car?
Could i get the part and replace it myself?...
I was able to find the EGR vacuum unit and tested that the bladder valve could hold pressure but wondered if the EGR solenoid has gone bad (found mounted on pass side strut).
any thoughts?

RE: check engine light -- P1400 code
 

EH!

THAT appears to be it!
I replaced the MDS part you suggested -- I think that the engine is running too hot for too long (going to change the thremostat as part of reg. maintenance).
Bacause that little sensor is all the way on top of the engine it got too hot.

Thanks alot for the tip! Saved me a lot of digging around!

RE: check engine light -- P1400 code
 

Before spending that amount of money on the MDP sensor- you should have tried removing in and cleaning out the little pinhole on the intake plenum that it uses to monitor vacuum. I have seen several issues where this little pinhole will get blocked due to carbon deposits causing incorrect MDP readings/operation.

Joel, CA

im having the same issue. could you please specify where this pinhole is? thanks

I have a Diamante 2001 that had a P1400 check engine code. I replaced the manifold differential pressior sensor or mdp sensor part # MD305600 and that took care of the problem. Advance Auto wanted $167 for it I got it from LKQ for $5. Pull-a-part may have some cars that may have it also because this part is used in many Mitsubishi modules.