Manifold/lambda problems

[jondee86]

Certainly... better to sample from the collector. But, there are any
number of aftermarket headers coming from Japan with the sensor
mounted in one of the primary tubes.

If it is a one wire or two wire sensor (non-heated) the end of the
sensor may need to be further into the gas stream. Does the end of
the sensor project out into the gas stream by the same amount as
when mounted in the factory location ??

Blacktop engines are well known for a mysterious mid-range stumble.
Sometimes a new sensor solves the problem.

Cheers... jondee86