Need ask about code p402
2 Answers
P0402 is an EGR code. https://www.obd-codes.com/p0402
Most common issues are carbon buildup inside the EGR valve or bad diaphragm inside the EGR valve or cracked vacuum hose to the EGR valve but it can also be triggered by other issues like EVP, DPFE, and MAP sensors. Step 1: Remove it, clean it and inspect diaphragm.