O2 sensor placement, Test and Tune only Options

[r_towle]

Instead of drilling and welding in a bung for an O2 sensor prior to the muffler,(clients car) how accurate would a tailpipe extension tube with an O2 sensor be?

Im thinking of a 1 foot long tailpipe extension with the O2 sensor welded in as close to the muffler as possible, yet without touching the stock system.

I intend to clamp the pipe in place with a stainless sleeve clamp so its air tight.

Any thoughts?
Rich

[r_towle]

I dont understand dead end..
Exhaust is always flowing by via the tailpipe when the car is running...yes???

Will it show lean or rich at the tailpipe?
By what average percentage??? I can do that math.

BTW, this is how the state emmission tests are done

[orange914]

I dont understand dead end..
Exhaust is always flowing by via the tailpipe when the car is running...yes???

Will it show lean or rich at the tailpipe?
By what average percentage??? I can do that math.

BTW, this is how the state emmission tests are done

maybe i didn't understand you. i think i see now your planning to bolt a section between the muffler and tip... no?

the o2 is different than the sniffer in operation. to create voltage the one wire o2 along with unburnt fuel relies on heat, the closer the hotter. it can be further downstream if it has "power wires" to self heat.

the sniffer has a pump to draw the sample across the bench to read the hc, co etc... and yes thats how ca. does the test. but it can have false readings if any air makes its way to it by a ex. leak, even huge tip pipes can influence it's readings. the c.o is what could be effected and be slow to respond and could have lean readings.

the closer the better as a rule, but not always practicle. also on a 914 system the exhaust doesn't mix until the muffler so you'd only get a single cylinder reading if very close.