Rich Vette

Aug. 6, 2019

Owners of a 2016-2019 Chevy Corvette equipped with a 6.2L LT1, LT4 or LT5 engine may experience the SES light on and a rich running condition. Technicians may find DTC P0172 and P0175 stored. The cause may involve the high pressure fuel pump on these gasoline direct injection engines.

If normal diagnostics do not isolate the cause of the rich condition, disconnect the dirty side of the PCV system and plug the vacuum supply.

Start the engine and monitor the fuel trims in closed loop. If the fuel trims return to normal, this is a good indicator that the high pressure fuel pump is leaking.

With this concern, GM reports that you will not see “a lot” of fuel in the crank case, so changing the oil may not isolate the concern. When the high pressure fuel pump leaks, the PCV will pull the fuel straight into the intake, causing the concern.