2006 Shinka, the CEL intermittently lights but no code is stored. So my wife drives around with a code checker attached, and even when the light is on there is no code. WTF?

 

Probably a Mazda-specific code that your reader doesn't understand. There are a few, one is for the OMP. Try to stop by a shop or Mazda to get it scanned with a better reader.

 

Is it a flashing CEL or solid?

What code check are you using?

You might try an ELM327 adapter with a phone app that can read mfr specific codes (IIRC, DashCommand and OBD Fusion have add-ons for specific cars).

 

Thanks guys. It's a Harbor Freight cheapie reader. Our local corner mechanic has a slightly better one, but not Mazda-specific. The OMP is so important I probably won't take the time to learn a phone app but go to a dealer.

The CEL is solid when it shows, BTW. Seems to come more often going uphill, never lasts more than a couple of minutes.

 

if it flashes and goes away it is a missfire, and really will not show a code. a code is a code. mabe check pending codes.

beers

 

Followup:

Tried 4 different phone apps:
1) Torque (recommended by my adapter company) just reads standard OBD codes, finds none stored. Maybe the paid TorquePro would be better but who knows?
2) DashCommand says there's a Mazda-specific code P12?? and that I need their add-in for more specifics. The app doesn't say how to get the add-in and my eMail of Saturday (5 days ago) about how to do it at what cost goes unanswered.
3) OBD Fusion costs $4.99, and has $9.99 add-ins for each manufacturer/year. Their customer service is prompt and superb. They were also very nice about refunding the purchase when the limited Mazda add-in failed to include anything rotary-specific, found no stored codes.
4) Car Scanner ELM OBD2 was probably the easiest to use, but only reads standard OBD codes. I uninstalled it.

Now for the kicker:

The dealership couldn't find a code, either. My wife got them to take it for a drive up and down South Mountain's twisty grades (after they'd already put on a good number of miles) and the CEL never came on. We were quite surprised there was no charge. I think the tech enjoyed the drive.

Bottom line:

We suppose it's nothing important. If DashCommand's add-in isn't too expensive we'll probably pay it and stand ready to check if/when while we see the CEL lit.

I can still say WTF now that the dealer says the same...

 

wow,
i am shocked. i use an ultragauge wired obd11 for temps and such on track. it has never missed a code, super cheap. maybe check out a dash command forum before you decide.

i will say it sounds like a missfire, and it will have to do them for a while before you get a pending code, much less a stored code.

beers