Test Description

NOTE: Test numbers refer to numbers on diagnostic chart (1 Of 2).

If bank 1 is operating rich, short term fuel trim will be near 112, and long term fuel trim will be near 118. These parameters are an average of all fuel trim cells.
Codes P0172 and P0175 set at same time indicates both banks are operating rich. Inspect components/systems that could cause this condition.
Inspect components/systems that will cause one bank to be rich. Visually/physically inspect all injector driver circuits for short to ground.

Fig 1: Code P0172 Schematic (Corvette) Bank 1 Fuel Trim System Too Rich

Fig 2: Code P0172 Diagnostic Flow Chart - 1 Of 2 (Corvette) Bank 1 Fuel Trim System Too Rich

NOTE: Test numbers refer to numbers on diagnostic chart (2 Of 2).

Ignition may have to be cycled a couple of times to build pressure.
MAF sensor could cause a rich condition. If rich condition no longer exists, replace MAF sensor.
If sensors appear to be contaminated, condition causing contamination must be repaired before installing new sensors.

Fig 3: Code P0172 Diagnostic Flow Chart - 2 Of 2 (Corvette) Bank 1 Fuel Trim System Too Rich