I replaced The older turbo manifold To the +90 machined turbo manifold and rebuilt my turbo. On the old manifold is where the O2 sensor is mounted so I'm going to move the O2 sensor on to the engine pipe about 3-4" from flange.


I had to wait for 4 days before I could get someone to weld a bung onto the exhaust manifold. During the 4 days the car seemed to run the same or even a little better. My gas mileage was 21 mpg about one more mile then usual.


Why would that be, I mean could there have been something wrong in the wiring because the O2 checked out O.K. I replaced the O2 sensor 2 weeks ago before I changed the Manifold.
Thanks for any help. Charlie