I've done something like this before but at this price point it's just great. My top mount doesn't have much clearance at the filter/inlet, I used a 1/8 npt male/female elbow and the gauge came out to the side.
Upgrade Your Car Diagnostics With 16 Pin OBD2 Extension Cable Splitter - Male To Dual Female Y Cable - 50CM
17 Review
Autoscanner for car diagnostics Rokodil ScanX Pro, OBD2 scanner
29 Review
Autel AP200H OBD2 Scanner Dongle - Wireless Bluetooth Code Reader with Health Status Reports - Diagnostic Tool for Engine, Transmission, ABS, SRS - OLS/BMS Resets - All Vehicles (Android/iOS)
11 Review
Vgate ICar Pro Bluetooth 3.0 OBD2 Code Reader | Scan Tool For Torque Android To Check Engine Light & Car Faults
19 Review