I have read, many times, that the header crack will affect the readings of the O2 sensor. What I don't understand, is how O2 enters the headers even though they are always under pressure. At boost, the pressure in the headers may be as much as 25 or 30 psig, and air AIN'T going to leak in against that much pressure. At low or no boost, the flow of the exhaust gas is probably too low to give any venturi effect, which might otherwise suck air. Anybody know how this works?
George W
Raleigh, NC
George W
Raleigh, NC