I'm trying to figure out whether or not I have a vacuum leak on my '12 Civic LX.. 150k miles.. been having a super rough idle, random shaking and vibrating. Acceleration is not good, lots of hesitation picking up speed. No check engine light.

I bought a BAFX Bluetooth OBDII scanner and the Torque app to take a look at some other stuff and copied down some of the vacuum / MAF / air-fuel ratio readings to see if they help.. thinking I might have a vacuum leak since I also sometimes feel like I hear air whooshing when I'm accelerating.. but again, no CEL.

Vacuum readings:

• When picking up speed/accelerating: 0.0 - 1.0 in/Hg
• Cruising at highway speed (60mph), foot off pedal: 23.6 - 24.2 in/Hg
• Idling/stopped in park: 21.3 in/Hg - 21.6 in/Hg, sometimes goes up to 22.2 in/Hg
• Idling/stopped in drive: 19.8 in/Hg
• When idling in park with a 22.2 in/Hg reading, I rev up to 2,000RPM and the vacuum reading goes to 23.3 in/Hg and right back down to 22.2 in/Hg when I release the pedal
• Cruising downhill at highway speed, foot off pedal: 24.5 in/Hg

My MAF reading bounces back and forth repeatedly between 38-45g/s while accelerating uphill. When cruising with my foot on the pedal it reads 3-10g/s. When first accelerating from a stop it jumps down to 0.0 - 0.3, then shoots up to 24.0-25.0, and goes back down and hovers at 22.0-23.6.

General idle RPMs are between 700-800, usually staying right around 730-740

I checked the Mode 6 test results on my Torque app and it had a few fails mentioned.. anything that would be related?

MID: $50 TID:$0c
02 Heater Monitor Bank 4 - Sensor 4
Misfire counts for last/current driving cycles(calculated)
Min: 372.95AFR Max: 1,974.6AFR
Current: 3,276.15AFR
FAIL

MID: $08 TID:$c1
O2 Bank 2 Sensor 4
Min: 7,472 Max: 4,387
Current: 65,523
FAIL

MID: $30 TID:$0c
Misfire counts for last/current driving cycles(calculated)
Min: 372.95AFR Max: 1,974.6AFR
Current: 3,276.15AFR
FAIL

The detailed chart results window mentions my air/fuel ratio as:

Air Fuel Ratio(Commanded): 14.85:1
Air Fuel Ratio(Measured): 14.68:1

Any ideas? Thanks!