I had the dealership run leak test and they said it checked out fine no major leaks! Also i bought the bov brand new.

 

Get rid of that bov for starters, that thing ruins drivability. Or you may need new plugs. But what your describing is the same question that have been asked more times then I can count. Those bov's suck on evo's.

Try your stock one, Im willing to bet the problem goes away.

 

Yeah i know that bov was bad move on my part everyone telling me it sucks! But do you really think that could cause that big of an issue?

 

Yes, if it is leaking.

 

how do you check if the bov is leaking? is there a way to check it?

 

Change it to a stock one.

 

yeah alright ill have to try that!

 

I've gotta ask, is your BOV atmospheric vent or recirculating? Becuase as far as I know, the stock Evo ECU assumes that it is recirculating the blowoff air back into the intake.


The reason that makes a difference is that your MAF and stock ECU calculates how much air is going into the intake just after it passes the filter. Then it goes through the turbo gets compressed and just before going into the engine, if you let off the gas the extra boost pressure built up in the manifold gets released by the BOV (woosh!)

The problem is, if you have a BOV that releases to atmosphere, now your engine thinks its getting 100 units of air but in actuality its getting 60 because a bunch has been dumped to the atmosphere. As a result it dumps in way too much fuel and can cause misfires and poor combustion. Having a stock style recirculating valve allows that air that has been accounted for to get back into the intake (after the MAF) so that the engine doesn't "loose" any of the air it has accounted for.

To use a atmospheric BOV on an EVO properly, you need to upgrade to standalone engine management that support such BOV's. The stock ECU doesn't like them.

 

Whether its vta or recirc, the problems will still exist.

 

actually i do have it recurculating i bought the whole kit for it

 

Do you have any kind of boost controller or is it stock lines. Kinda sounds like its running off stock actuator pressure but that is 10 psi I think. Take it to a reputable performance shop in the area and they will be able to diagnose it quick I bet. Mitsu dealership is full of guys who have no idea what they are doing. One time I was told that stock boost was 10 psi and he had no idea that the stock boost lines had pills in them that allowed for 17-19 psi.

 

No i dont have any type of boost controller all i have is an intake and the bov! yeah i didnt they knew what they were talking about

 

Hello. So what was the problem. My car is doing the exact same thing now. I am always getting the p0300 code but now my turbo it acting stupid. I can't go over 4000 rpms . Its like it stuck with no power. Only mod is a intake. The bov is stock.

 

my turbo just went out at 119,000 miles, it would spool fine then you would hear a squeeling noise, then boost would not climb any higher than 14psi, it got worse the longer i drove, within a week it would not boost past 5psi. the other thing you need to know is the turbo is only as good as the exhaust, if the cat got clogged or somthing like that it would slow the turbo.

 

I'm sure its my Turbo. Did you place it with a stock or aftermarket one? What's better. I was going to replace the clutch but it looks like a Turbo first. I just finished paying it off LOL.