When my car starts it idles high almost 1500 and the vacum is around -12 to -14 on my boost gauge.
Also my A/R seem to go from 14.7 (normal) to 17.x, when the car goes to 16-17 to 1 thats when it start to shake and almost stall. My lights also dim when it does this.
Once the car warms up it gets a little better.
I'm just worred because low vacum means motor damage.
catless exhaust with uppipe