Smoothing Prius Rough Running Condition

Some 2010-2015 Toyota Prius and Prius PHV and 2012-2016 Prius V vehicles equipped with a 2ZR-FXE engine may exhibit a rough running condition with the MIL on and DTCs P0300, P0301, P0302, P0303 and P0304 (misfire codes) during light acceleration while the EGR system is active.

Toyota says to replace the intake manifold to address this condition, using the updated intake manifold P/N 17120-37054, along with EGR gasket 25634-37030. Note that this fix only applies if the condition occurs during EGR operation while driving. During a road test, the EGR can be disabled by disconnecting the EGR connector to verify the condition.