Monitoring lean burn

[justjohn]

Alright, so I got an HX ('96, so OBDII) and I want to get instrumentation, but not sure which way to go. So first, is the following correct?

If I get a scangauge II it will screw up the readings whenever I go into lean burn, but I can program it to tell me when it enters lean burn.

Ultragauge will also be thrown off by lean burn and can't show it via custom gauge but can at least tell by watching when the rear 02 sensor goes to zero volts. Also cheaper.

MPGuino will give accurate readings but is harder to install and can't clear codes. Cheapest.
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I am not opposed to a little digging/learning; haven't done any soldering but have tools/help at my disposal. Need ability to clear codes unless I do an exhaust swap.

Given that, what option sounds best? I'm thinking either [Ultragauge + possibly a home rigged lean burn indicator] or [MPGuino + definite home rigged lean burn indicator and either exhaust swap or OBDII scanner*]


*thought these could be had cheaper, but essentially cost as much as an ultragauge so at that point I might as well get an ultraguage too, which would be kind of silly

[justjohn]

Creeping up near 100 views and no replies. Hmm.

Well I've done more reading since this and I'm still not completely satisfied with any options I can come up with. It looks like one HX owner on here uses both a scangauge and an MPGuino. I'd really rather not do that unless it's necessary though.

[justjohn]

Well, just got my first check engine light and since I'm not replacing the exhaust in the next 2 days Ultragauge just got promoted to the front of the list.

Maybe mpguino later. Would really like to have accurate lean burn numbers as well.

[mwebb]

look over the list of Parameter IDs PIDs in Ultra gauge and Scangauge to see if
"Air Fuel ratio " is on the list or
"Current lambda "

real scan tools have these PIDs but Scangauge is not a real scan tool and Ultragauge is not a whole lot better although it is the better of the two .

MPGuino will show you real time FE in MPG and Gallons per hour
when your system changes to "lean Burn" you will see your real time FE improve , so even though you do not know actual AFR you can see when the improvement happens and when it stops .

so
MPGuino is your best choice imho
or
make your own instrument cluster using this software with a small notebook or laptop - this software does have an AFR PID

and it does cost less than scangauge, you will need your own laptop or notebook

OBD-2 Scan Tool Browser Virtual Dash Board screen shot

OBD-2 Vehicle Explorer Scan Tool Browser

[basjoos]

If you can get your hands on a SuperMID, they show the injector pulsewidth and it is easy to see the pulsewidth shift as it goes into and out of lean burn. Some people have hooked up a voltmeter to the oxygen sensor and watched for the voltage change as it enters and leaves lean burn. Once you know the voltage for lean and non-lean burn it is easy enough to design an LED output that would come on when the voltage was in the lean burn range. For more info go to gassavers.org and search the forum for "lean burn monitor".

[justjohn]

Yes, I know OBDII gauges are pretty much worthless for monitoring fuel economy for my car. However, I need a handy way to clear the check engine light, and according to this guy I will at least be able to detect lean burn:

I have recently installed an inexpensive ($60) Ultragauge. I can monitor the front and rear oxygen sensors through the OBD port. Lean burn is easy to detect, the rear sensor goes to zero.

I would like to replace my exhaust with a stock one at which point I wouldn't need the OBDII functions anymore and would be able to go MPGuino. If/when that happens I will probably try to rig up a lean burn indicator as well so I can still track that easily.

Any other tips or suggestions welcome of course.