Not sure what to make of this
In the past month or so, I've noticed some power loss in my WRX amongst some other things. Here are some of the things I've been noticing.
1. Autometer mechanical boost gauge is now showing below zero when the car is completely off. Not sure if this is causing my boost to read incorrectly now or I am not actually building the amount of boost I was before which was around 12-15lbs. Now it seems to be about 9lbs. At idle, vacuum is around 20-22. I don't remember what it was before I started noticing these things.
2. Appears to struggle a bit on starting. Doesn't matter if it is a cold start or if the engine is still warm. Just seems a little hesitant. I have tried turning the key to accessory for 1-2sec first before kicking over, but there was no change in how it has been acting.
3. Appears to be running rich. I'm noticing quite a bit of exhaust popping like it is loading up. Usually this happens between shifts. I tried sitting in my driveway and revved up to 4000rpm and let off. I heard a very loud pop that sounded like it came from underneath the car.
HKS Intake, exhaust, downpipe, BOV
I had the dealership replace the clutch and pressure plate about 4 months ago cause it was going bad. About 3 months ago, I had the dealership do the 40k service. I'm at 38k mileage now. I have searched for any leaks and such, but no luck. I'm just very baffled by this.
Thank you in advance for any suggestions y'all may think this might be.