Originally Posted by Lordhowe
well the dyno is at www.xcoticmotorsports.com
in PA and it's the same exact dyno i went before. they always plug something under the window washer fluid canister and then a read out at the end of the tail pipes.
They're connecting a tach lead under the washer fluid reservoir... allows the dyno computer to see engine RPM. They're reading AFR with a wideband oxygen sensor at the tailpipe. A tailpipe wideband O2 sensor is common at tuning shops because it's easy to connect to basically any car.
Are you catless? If so, that could be the problem with the AFR readings... if the shop expects the O2 sensor to get readings after one or more cats, it might be calibrated for that. Without any cats cleaning the exhaust, the sensor would see richer exhaust.