(I'm not taking credit for this picture....)

There is a hose from the Fuel Pressure regulator to the intake manifold. Mitsu did not put any type of clamp on this hose. It will pop off and cause you to run lean, and ruin your idle. It is a simple vacuum line, but is difficult to see when trying to diagnose a problem...

The hose is located near the dip stick. All you need is a couple zip ties....

Heres a pic.



There are one 2 many "My idle is shaky" thread on the opening page..... this is likely everyones problem....

 

This should go in the known issues sticky. I wont take credit for that idea or the picture or the discovery.

 

I was happy to find this picture in another thread LOL, kept me from breaking out my digi cam

 

It should cause it to run rich. It's the FPR hose.

 

hmm I wonder if this applies to Ralliarts too?

 

The boost levels on the RA probably won't be high enough to pop it off as easily as the evo.

 

had this happen about two weeks ago. the car idled like crap from the vacuum leak and since it ran to the FPR the pressure wasn't raising with boost so it ran really lean, like 16 to 17:1. luckily i took a min and took the engine cover off and saw it immediately.

 

Thanks for the pic!

 

I had the same issue last week

 

it isn't a question of if it will happen.....it is when it will happen..... prevent this before it happens to your car.

You really end up feeling like an ******* sitting next to someone at a red light and your car is stumbling all over itself... especially when your exhaust is loud as hell and makes sure everyone in the immediate area can here your car almost dieing LOL.

 

thanks

 

Noob question:
If it's a vacuum line, what is causing it to pop off? I would understand if it was under pressure...

 

It's not exactly a vacuum line - it's tapped into the intake manifold so it see's intake pressure under boost.

 

did that and mi idle is still going crazy, i hope the tune takes care of it

 

I had this happen last week as well, took me forever to figure it out... thanks for posting this picture