So I've been trying to figure out for the last couple weeks why my car is slower then normal, where ppl figured I wasn't hitting boost. I've been researching and asking what could be the problem with no such luck. Also noticed yesterday at idle, mainly stopped in traffic yesterday, my rpm's were going crazy on its own, like if i was tapping the gas to rev it, that's what it was doing on its own, from idle 750 up to 1000 and even dropped almost to 0, I thought my car was gonna stall. I was freaking out. Car was shaking.
Then today after someone saying to check the pcv valve connections (which were fine), I noticed a hose right by it, a small one, completely disconnected. I'll post pics at end. Can anyone tell me what this hose is, and what's connected to at both ends? Could it have anything to do with my power loss/transmission acting messed up??

 

look it up... its normal on the evo x that the fuel reg vac/ boost line blows off... just zip tie it up and it will not come off next time

and yes a vac leak will mess with the way the car drives and idles...

 

Yeah this was a common problem for the Evo X guys. It's a vacuum line, and an important one at that. That's the line that helps determine how much fuel to feed the engine. Just zip-tie it, as the poster above mentioned. Your problem will be solved.

 

The car will also run dangerously lean at full throttle with that vac hose off like that.

- Bryan

 

In that case, should all of us Ralliart owners be ziptying our vac hose on as a preventative measure even if we're not currently experiencing any problems?

 

Well I put it back on and zip tied it and drove around and car is slower then it used to be. i can't figure it out

 

Yes but use the little zip ties, not the standard size. The little zip ties work much better there.

- Bryan

 

Reset the ECU. This will bring the fuel trims and such back in line.

The fuel trims where probably maxed out positive trying to richen the car up from running lean with that hose off and that will cause the car to run rich at WOT as well.

- Bryan

 

thats the fuel pressure regulator your car would be sucking in non metered air creating the problems you said

 

Also check the pvc valve it self and make sure that its not stuck open or closed. my pcv valve was leaking and was giving me a boost leak.......

 

how do i reset the ecu?

 

Disconnect the negative terminal for a few minutes. Tap the Brake pedal to quicken the discharge. Reconnect the battery and drive normally.

 

Okay, thanks. I'm going to try it this morning and drive it around and see.

 

I just zip tied my vacuum hose just to avoid this issue...everyone of us should