I reflashed my ECU with DPF off code supplied by fapswitch. The car occasionally goes into limp mode, with Anti-pollution and ESP fault messages on the screen. I've now acquired a Chinese Lexia copy, and wrestled with the software until it communicates happily with my car. I found that there is a P0402 fault code stored. I erased the fault codes, and will drive it to see if it recurs, but what does P0402 mean on this car? I have blanked off the EGR valve - would that make a difference?

P0402 is EGR related error code. When you blanked the EGR you stopped the flow of the exhaust gases back to the engine and you start pulling more clean air through the MAF meter. The ECU senses the bigger flow of air through the MAF meter and shoves the error code. Removing the blanking plate or making EGR off in the software will fix your problem.