DTC U2021: Notes

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

To warm up the engine completely, idle the engine and wait for more than 5 minutes.

Fig 1: DTC U2021 Detection Condition And Possible Causes

Courtesy of MAZDA MOTORS CORP.