MY 02 Impreza O2 Sensor

[Charlie Mass]

CEL code indicated upstream O2 sensor. Replacement quoted at $180!
Autoparts guy suggested cleaning sensor. Where the heck is this sensor
located? Been searching the web all morning for schematic or even a
picture of the sensor with no luck. Also read that Bosch Platinum
plugs can degrade and cause CEL to throw this error. Anyone know this
to be true?
Thanks.
cm

 

[y_p_w]

CEL code indicated upstream O2 sensor. Replacement quoted at $180!
Autoparts guy suggested cleaning sensor. Where the heck is this sensor
located? Been searching the web all morning for schematic or even a
picture of the sensor with no luck. Also read that Bosch Platinum
plugs can degrade and cause CEL to throw this error. Anyone know this
to be true?

Don't know about the other stuff, but my mechanic (a Japanese car
specialist) told me to stay far, far away from Bosch platinums. They
used to use Bosch platinums, and they told me stories of finding the
center electrodes eroded or broken off. They're made with a thin
platinum wire buried flush at the end of the ceramic insulator.
Bosch claims it gets hot and self-cleans, but without melting away.
Real world evidence seems to be contrary.

They currently use Denso plugs, even though a lot of the makes they
service only factory specify NGK.

 

[ed]

Very unimpressed with the Bosch Platinum. The center electrode does indeed
erode away into the porcelain, then the spark has to travel up the porcelain
to get to the ground electrode. The set I tried wore away within 10 k km
(6000 mi)or so, and the vehicle was harder to start and did not run like it
normally should. When I put in regular plugs, the car started easier and ran
better.

 

[Gilles Gour]

Very unimpressed with the Bosch Platinum. The center electrode does indeed
erode away into the porcelain, then the spark has to travel up the porcelain
to get to the ground electrode. The set I tried wore away within 10 k km
(6000 mi)or so, and the vehicle was harder to start and did not run like it
normally should. When I put in regular plugs, the car started easier and ran
better.

I have been using NGK platinums and am very satisfied. Will try their
irridium plugs next time just to see.
96 Brighton with 140 K
Gilles

 

[y_p_w]

Very unimpressed with the Bosch Platinum. The center electrode does indeed
erode away into the porcelain, then the spark has to travel up the porcelain
to get to the ground electrode. The set I tried wore away within 10 k km
(6000 mi)or so, and the vehicle was harder to start and did not run like it
normally should. When I put in regular plugs, the car started easier and ran
better.

This should have a picture:

<http://www.boschusa.com/AutoParts/SparkPlugs/Platinum2>

Although this is the Platinum2, all of their platinum plugs have a
center electrode flush with their insulator.

 

[dhf]

That's interesting as my experience with the Bosch platinum, single
ground electrode, plug has been very favorable. I've had them in my 92
SVX for over 25k miles and although I haven't taken them out to examine
electrode wear, they haven't caused any hint of misfire and the car
starts quickly. I just came back from a 2000 mi. high speed road trip on
which I averaged 26.5 mpg so the performance is obviously there as I'm
sure I would have noticed any misfiring in reduced fuel economy.

 

[Chris Phillipo]

Subject: Re: MY 02 Impreza O2 Sensor/Bosch Platinum
From: (e-mail address removed) (dhf)
Newsgroups: alt.autos.subaru

That's interesting as my experience with the Bosch platinum, single
ground electrode, plug has been very favorable. I've had them in my 92
SVX for over 25k miles and although I haven't taken them out to examine
electrode wear, they haven't caused any hint of misfire and the car
starts quickly. I just came back from a 2000 mi. high speed road trip on
which I averaged 26.5 mpg so the performance is obviously there as I'm
sure I would have noticed any misfiring in reduced fuel economy.

The problem I alwys had with them is they foul within a week. Not a
problem if your car doesn't burn any oil I guess. Regular plugs worked
fine in the same motor so I stuck with those.

 

[y_p_w]

That's interesting as my experience with the Bosch platinum, single
ground electrode, plug has been very favorable. I've had them in my 92
SVX for over 25k miles and although I haven't taken them out to examine
electrode wear, they haven't caused any hint of misfire and the car
starts quickly. I just came back from a 2000 mi. high speed road trip on
which I averaged 26.5 mpg so the performance is obviously there as I'm
sure I would have noticed any misfiring in reduced fuel economy.

It's not that they always cause problems, but that there seems to be
an inordinate rate of problems. Also, many of the problems reported
with the Bosch platinums seem to happen in smaller, hotter running
engines. If I recall, the SVX has a 6-cyl engine under the hood.

However - I still feel that sticking with factory plugs is the best
way to go unless you've modified the engine, esp with an ignition
system upgrade.