Home built exhaust analyzer?

Hank Winning · Post by **Hank Winning** » Sat Jan 05, 2002 9:14 pm

Does anybody know of a way to build a exhaust gas analyzer using a oxygen sensor -a dwell or maybe a mulitmeter.
I was wondering if stuffing the oxygen sensor into the tail pipe to see what you get would worth while?
Has anybody done it
thanks
hank

Sidewalk · Post by **Sidewalk** » Sat Jan 05, 2002 9:22 pm

http://www.students.tut.fi/~eppu/dev/EGO-bar.html

------------------
'59 bug-unstockStella
'88 Bronco II-unstock Sonja

brian rogers · Post by **brian rogers** » Sun Jan 06, 2002 2:54 am

A few months ago there was a post on Cal-look forum about useing an O2 sensor and multimeter for air/fuel ratios relating to carb jetting. Same thing is used in EFI for closed loop operation. It might pay to queery there.

Hank Winning · Post by **Hank Winning** » Sun Jan 06, 2002 9:57 am

thanks for the leads
hank

Veepster · Post by **Veepster** » Tue Jan 08, 2002 10:59 am

been doing it for years.....run lead from O2(assumng 1 wire O2) to positive of multimeter and negative from MM to vehicle ground....500mv is 14.7:1

Bruce2 · Post by **Bruce2** » Tue Jan 08, 2002 1:28 pm

Get a 3wire heated sensor, a Bug idling doesn't keep an unheated one hot enough to return proper values. You can't put it in the tail pipe since there will be oxygen dilution from air being drawn back into the tailpipe, unless you put a long extension on the pipe after the O2 sensor. Best bet is to weld a threaded bung on the header and use a plug when driving. The threaded bung is simply a Bug steering wheel nut. Most of the late Bugs have the right M18x1.5 thread.
Less than .5V is lean and greater than .5 is rich. You will never be able to set it at .5V. I shoot for around .75-.85V. Over .9V is getting too rich.

regis101 · Post by **regis101** » Tue Jan 08, 2002 6:19 pm

Greetings. Good call, Bruce2. " Necessity is the mother of invention." There is a similar question in Bus Barn. I read a post that said that 20 inches from the head is a safe place for the O2 sensor. I also like the idea of a three or even a four wire sensor. One could land the wires onto a terminal block in the engine bay for a clean installation. Happy Trails

speedbuggy16v · Post by **speedbuggy16v** » Fri Jan 25, 2002 8:54 pm

there used to be plans for one on pelican parts website

FlatFourFanatic · Post by **FlatFourFanatic** » Sat Jan 26, 2002 4:18 pm

What an awesome thread. Who needs NASA when you guys are about.

pbanders · Post by **pbanders** » Wed Jan 30, 2002 9:30 am

Be aware folks: the O2 sensor-based meters aren't very accurate. If you need it to do much more than just lean/stochiometric/rich, you should consider buying a shop quality CO meter. See the disclaimer in the URL for the DIY meter listed earlier in this thread.

Brad Anders

Hot Wheels · Post by **Hot Wheels** » Wed Jan 30, 2002 4:16 pm

They use to sell a pretty cheap unit in JC whitney a few years ago that was a weld in sensor and a rich lean guage. It used to be cheaper than a good meter and sensor but how accurate? Worked well on the vehicle we were working on.

Phantom · Post by **Phantom** » Thu Jan 31, 2002 4:00 am

As already said - these sensors can only really tell you if the mixture is rich or lean. If you are after actual A/F ratios you could use a universal oxygen sensor.

I think NGK make one (UEGO sensor) and Bosch make one (LSM11 ???). These are expensive and require some expensive electronics as well.

There is a company in Sweden I think (can't find the website at the moment) that sell a complete kit. It costs around 500GBP (800USD ?) though !

PapaG · Post by **PapaG** » Thu Jan 31, 2002 9:25 am

http://www.diy-efi.org/diy_efi/projects/diy_wb/

A typical OEM switching type O2 sensor will not work with this project. This
project requires a 2 cell wide band O2 sensor that was used on a lean burn
Honda Civic. It is available from Honda dealers, and from www.hparts.com.

Application/part number:
92-95
Honda Civic
1.5 VTEC
36531-P07-003
W-SENSOR, OXYGEN $243.68

The generic NAPA equivalent may be cheaper, but may not be widely available:
Part number OS791

The thread on this sensor is 18 mm x 1.5 mm pitch.

Mating connectors can be found on Civics and probably other Hondas, even if
they weren't lean burn. Try looking at:

the headlight harness,
near the brake master cylinder/booster (yellow wires with different color traces),
on the passenger side fender near the firewall,
90 accord distributor connector

The original manufacturer of the connector is Sumitomo. This connector
is from the HW Sealed Series 090

Hope this helps

[This message has been edited by PapaG (edited 01-31-2002).]

bl67vw · Post by **bl67vw** » Thu Feb 07, 2002 1:08 am

this may be off topic and away from the do it your self idea, i used one of those cheep guages with a 3wire sensor before and it was about useless imo, i will be going to fuel injection with a turbo soon so ive been giving alot of thought into geting my mix right becoause an error under boost can be fatal for the engine. Anyway here is the best solution i have found for the problem http://www.geocities.com/francillion/main.html#PRODUCT its still a bit more than i wanted to spend but i dont think they get much cheaper than that (with a wide band sensor)

regis101 · Post by **regis101** » Thu Feb 07, 2002 9:48 pm

Greetings. I am installing a four wire sensor this weekend for tuning purposes. There are numerous brand names out there that sell gauges. Some digital and some analog. I'd like to have a gauge up front in the Westy. The distance would be about 20-25 feet from the sensor. Now, I'm thinking, that since the sensor generates .5 volt ( avg. ), will I get a voltage drop that is enough to give a false reading.? You'd think this would be engineered into the gauge. Lastly, I wonder if it takes more or less to drive one or the other of the gauges. I dunno