cliffyk

Block the throttle open, block one exhaust tip with a rag and hook a shop-vac to the other--let it run for 30-45 seconds and then while it's still running do the "free-air" calibration. There will be 2 or 3 intake valves open or partially open, and as the sensor reads to oxygen content of the gas to which it is exposed it will properly calibrate.

The first time I did this I pulled the sensor, did a "real" free-air calibration, and logged the AFR over a 10 mile trip. Then I did a shop-vac calibration and logged the AFR over the same 10 miles--loaded it all up into Excel and the average logged AFRs were within 0.07% of one another...

dwtjr3

Wow thats a good idea. Should i pull the pipe off of the throttle body Or is just propping it open enough?

97stanger

has anybody ever used this?

http://www.aemelectronics.com/no-wel...-2-5-inch-1174

seems like a good idea, I just wonder if readings would be similar to a bung being welded on the midpipe,

cliffyk

It's stupid--you still have to drill a hole, and it's $17 more than any mom & pop shop would charge to weld on a bung...

cliffyk

Nope, just block the throttle open, I use a smallish block of wood between the bellcrank and the stop screw...

97stanger

but you can just do it laying in the driveway

cliffyk

I drilled the hole using s 90° electric drill and a step bit, then wrapped a beer can (Budweiser) around the pipe held with a couple hose clamps and drove to "The Fat Man's" muffler shop some 5 miles up the road...

97stanger

^ haha nice

I'm not sure which route I'm going to go on the bung, but either way I'm sure the gauge will work well

WannaBeGearHead

That's stupid and overpriced. Take the wonder out of it and get it welded in.

97stanger

^ sir, yes sir!