I know there have been a ton of posts on here about getting rid of this code and how difficult it can be to pinpoint. There was a vauge myth at one time about this code being present on 99 cars with a turbo kit due to the fuel system. Well, I've had the code for the past 3 years and just put my fuel system back to stock last Saturday and the code went away. Ran a scanner, no codes. So ... myth confirmed.

1999 Eclipse GST 4G63

so what in the hell was causing it? I thought it was because the boost was messing up the vacuum in a diaghram above the fuel tank and it was tearing it causing a vacuum leak. This isn't true? How the hell can we fix this without going back to stock?

It's on my long list of things to fix right now. I have to get my emissions tested once I put the motor back in.

Fully Built MS powered 99' GS Sport, Garrett T3/T04e 60 trim with one big ass intercooler!

Yeah, she runs...sorta!

if thats the case couldnt you put a one way check valve on the vac line so that is see vac only and never boost?

is this the line that use to connect to the 3 prong T on the mani and ran to the back of the car. i found mine capped off with a screw.

1999 GS, 420a, Airwerks K26 Turbo, All custom piping, Tial 40mm WG, Tial 50mm BOV, Apexi SAFC II, AVC-R and turbo timer, 255 walbro pump, 38lb INJ, Venom Fuel rail, FMIC, 60mm Modern Performance TB, Ported Mani, AGX struts, 19" Rims, blah blah blah....