well i finally installed my VDO boost gauge on my car. i hooked everything up, started the car...idled at 19-20 in hg...so i drove it...floored it on second and third gear and it went to 10psi!! i tried it again and in first gear...10 psi. My car is throwing out a 300 code and the service engine soon light is on. the idle is rough...and hoveres anywhere from 800-1100rpm. my car is stock. i bought it used, it looks like it had some modifications done to it prior to my ownership. any ideas here???? i knew my car felt slow.

edit: the 300 code went away when i used shell gasoline and got the ecu flashed

 

EDIT:Oops, thought it said boost controller, Hmmm, that could be a boost line loose or vacuum line. Sorry for any confusion.

 

what do you mean by backwards?

 

Sounds like somebody probably had a manual boost controller on it before. When they took it off they didn't replace the vacuum lines with the "pill" in it, causing your boost to be very low. Just a guess. They probably just ran a line from your wastegate to the turbo outlet which makes you boost at only 11 psi. As for the engine code, no idea.

 

i'm pretty sure it had a mbc on it. i know it had a boost gauge on it. which vacuum line is this?

 

https://www.evolutionm.net/forums/sh...ighlight=forge

 

thanks man.

 

Good Luck, hope that was it. Its an easy fix. I'm assuming you don't have the original hose, but you can get it from Mitsu for like $25

 

well i finally got around to replacing that hose (the one from the wastegate and turbo to the solenoid)...same result, still boosting at 11psi. the kit i bought from mitsu came with 4 hoses...i just used the really long one...should i replace all the hosaes that it came with. this is really frustratiing

 

The only thing that should matter is the two shorts hoses with restrictor pills in them that go to the tee. YOu have to make sure you install the correct one to the turbo nipple and the correct one to the wastegate actuator.

I can't think of why there were 4 hoses, though, unless you are referring to the very short hoses with restrictors pills as 2 of the 4. If so, then here they are:

1) BCS port closest to firewall - to MAF pipe
2) BCS port closest to radiator - to tee
3) Turbo nipple - to tee (short hose with restrictor pill)
4) Wastegate actuator nipple - to tee (short hose, not sure if this one has a restrictor or not)

I am pretty sure there are 2 restrictor pills, and I KNOW one of them is in the short hose that goes to the turbo nipple, but the 2nd one is either in the wastegate line or the long line that goes from the tee to the BCS.

 

i had the same problem with my evo and i replaced all the hoses.

 

1st and 2nd gear dont really tell you the story of how your boosting .. Do a full run in 3rd gear and look @ your boost gauge and tell us where it peaks and where it tapers to ..

 

cool, i'll go replace the two short hoses now. i'll let ya'll know if that did it

 

Get a MBC

 

ran out of daylight before i could replace the other two hoses, but after putting my car back together (took out the battery and stock airbox)...my cars idle is all sorts of messed up. it sticks at 1300-1500...this also triggered my 300 code to come back. any ideas here? im plan on driving the car back home (300 miles away) tomorrow evening.


i did have an mbc on the car, but im returning it to stock b/c i'm selling it.

also...did disconnecting my battery erase the 300 code flash fix mitsu put on my car?