Hi everyone,
my mate has a Honda accord 1998. the engine magement light came on , he took it to the Honda dealship who said it was a valve that had something to do the the emmisions. The mechanic said sometimes you can clean the valve but they are better replaced at a cost of 290 quid plus labour.
My question is,
What exactly is the valve
If he replaces it himself does the ecu resett itself or does he need to go to a garage to get it reset.
Is it worth it to use a second hand one

Thanks