I've searched the many threads containing the boost spike issue but none seemed to be exactly the same as my issue. First off, I have a 02 WRX with an HKS catless downpipe, a catless uppipe, and running stage 2 with my Cobb AP. I have about 77K on it and the UP/DP/Stg 2 were done about 3 weeks ago.
The issue I have is that sometimes in 3rd and 5th gear, my boost seems to spike around 3000 rpm, making my rpm jump from about 3K to 4K then back down and steadily back up. Seems like common boost spike after doing exhaust mods. I read my boost at these times with my AP, and it never jumps over 16psi, so I'm assuming its ok. But its wierd, because the boost doesn't actually spike. It increases when my rpm's spike, but the boost never backs down.
I would like to resolve this issue if possible. I have read about adjusting the wastegate arm, but I haven't done it because I am hitting target boost without any noticeable flutter, so I didn't want to mess with it.
My questions are: Could a leaky boost gauge install cause any spike issues?
Can a leak in the downpipe to catback connection cause any spike issues? (I still have the stock catback, but my DP doesn't seem to fit right because I don't have the stock donut gasket)
I know my boost gauge is inaccurate compared to the AP, so I am going to make sure something didn't come loose ... is there anything else I should check on? Thanks in advance for any advice or help.