exhaust gas analyzer

[Rrrockhound]

Does it matter what kind I buy? What about calibration? Does it make sense to buy one used off ebay?

[Bleyseng]

I like my LM1 meter......

[Dave at Pelican Parts]

What are you using it for? If for tuning the car, you can't beat a Wide-Band O2 (WBO2) meter like the LM-1. Unlike it's (cheap) narrowband counterparts, it will actually tell you the engine's air:fuel mixture, rather than "it's lean" or "it's rich". (The gauges you get with NBO2 meters are bogus; the only thing an NBO2 sensor can tell you is if the mixture is at stoichiometric [14.7:1], or richer than that, or leaner than that.)

If you're trying to set up the idle mixture, a CO meter can be useful. The stock specs are listed in % of CO in the exhaust.

I personally feel that the WBO2 is the only way to go. I have an NBO2 meter in my car now, and it's just this side of absolutely worthless.

--DD

[Rrrockhound]

Mainly I want to use it for setting the idle mixture, and possibly for troubleshooting. I'm really only interested in air/fuel ratio. I found this on ebay but I have no idea as to its functionality or condition. Even if it's in good shape, how would you know it was calibrated correctly? In my line of work, I use numerous electronic measurement devices for air and water chemistry, and you would never consider trusting any of them without calibrating them first.

[Dave at Pelican Parts]

Looks like a CO meter only. I don't know how you'd verify it, but I imagine the instructions have something to say about that. Hopefully they don't read "bring it to your local [now long out of business] calibration center"...

That can tell you about your idle mixture, but for troubleshooting (and setting the idle mixture) I think the WBO2 is the way to go.

--DD

[pbanders]

If you want to know your CO/HC/AFM accurately, you need a shop-quality meter. A WBO2 is a good approximation, but a calibrated meter is the standard. You can get a used Sun meter from Ebay, in good shape, expect to pay $500+ for it.

The alternative is to go to a local shop and pay them when you need an accurate reading. For most owners, I suspect this is the best approach. If you've got a well-working D-Jet stock setup, with an un-mangled manifold pressure sensor in good shape, the only thing you need to set is the idle mixture, something you can do in less than 5 minutes.

[Rrrockhound]

Oof. Those LM-1 units are pretty expensive for a guy just noodling in his garage. As important as A/F ratio is, seems like there ought to be a cheaper, simpler way to check it than making special arrangements to take the car to a shop.

[Bleyseng]

Dyno time is pretty cheap cuz you should only need a hour. They will run some A/F tests at WOT and Cruise (partload) so you will know where its at.
If you need to add alittle richness you can increase the fuel pressure at the dyno shop to correct some.
Otherwise you must open the MPS to adjust the inner/outer screws and then set the WOT settings.