02Vortech

iTrader: (4)

would an exhaust leak the size of a dime cause a wideband to read leaner that it really is @ partial throttle?

chino_man279

iTrader: (7)

Any leak upstream of the wideband sensor will skew the output of the sensor. It reads available oxygen in the exhaust stream. Even without a leak, the numbers output by the sensor are way off at partial throttle with a high overlap camshaft. The overlap period basically shoves oxygen straight through the exhaust from the intake.