On 4/22/2011 9:35 AM, peter wrote:
> On Apr 19, 2:04 pm, > wrote:
>> On 4/19/2011 7:34 AM, peter wrote:> hi guys,
>>> swmbo's 95 m-ed is throwing a code and i forget how to get the lite to
>>> blink out the codes.
>>> i thought it was jump 10& grd but alas it isnt, any hint?
>>
>> Try Miata.net
>
> it was indeed 10/grd but
> warm car up, turn off, turn key to on but dont start, watch the
> blinks.
> code 17 o2 sensor.
> i thi k i put a bosch o2 unit it before i found out they are not the
> best. what brands are better?
>
> thanks,
> peter

What I found was that some Bosch alternate part#'s were better than
others. However, that was with four wire sensors.
If you get into using the aftermarket replacement sensors, it's a good
idea when you still have problems to make sure that the old and new
sensors have a reasonable match.
On the 99 NB's, the sensor response times can cause problems in the test
cycle. The 95 NA's should not be as picky.

I had a "slow" front sensor, and a "normal" rear sensor. There were
intermittent codes set, claiming the Cat efficiency was bad.
Replacing the front sensor seemed to make a big difference, but a Cat
efficiency code would still set on a rare and intermittent basis.
The output voltage on the bad front sensor was well within spec.
The usual failure circumstances involved a fail during the morning run
to work, or the next morning at low speed after a five hundred mile run
on interstate 75.
The whole problem turned out to be one of those combinations that are a
pain to deal with.
When all was said and done - -
New coil packs finally eliminated the very occasional Cat efficiency
codes. The only direct symptom of a possible bad coil pack was a
slightly rough "feel" at an RPM/power/load setting that is transient as
gears and throttle settings change. No coil related codes were set.

One of the issues was that a new Cat would make the Cat efficiency code
go away until it was fully "broken in".