2003 wrx Cold start vac leak shaking engine rough idle. I'm putting this out there in the hopes that I will find a quick and easy fix, and if not it will log my efforts. This is more of a small annoyance than a big issue. I believe this is a very small vacuum leak. In the first 3 minutes after start up the car will often have erratic idle and a bouncing shaking engine at idle. When driving the car is perfectly fine. I do notice a bit of hesitation at stops sometimes in the first few minutes. Once the car warms up everything runs perfectly and idle is much smoother. This is annoying. When the vac is at -18 on the gauge idle is super smooth, as it bounces up to -15 or lower the idle gets rough. When the car is warm, its pretty steady at -18 at idle. I had a larger leak that was fixed by just messing with the hoses, this is very minor. One point of contention is that its got a bov with the included crappy plastic hoses. Those will be replaced with rubber lines. Also, it has those little filters on the bov lines. This might fix the issue. Bov is HKS SSQV newest version. I just bought the car a month ago. Very clean car. This is my 3rd wrx with this same bov setup. Never had this issue. Mods: huge intercooler, up pipe, downpipe, no cats, bov, stock intake. Any suggestions? Thanks!
Amazing what swapping out those crap plastic hoses can do. Smoothness at idle. Dropped vac a tiny bit. Good stuff!
