On 4 Aug 2018 07:56:20 GMT, Clare Snyder wrote:

If it was P0133 it means slow response - definitely a bad sensoe

I think that's what it was, but what only matters now is what comes back!

BTW, I just bought oxygen sensors for three different vehicles, where I
*hate* throwing parts at a problem. I just hate it.

But it turns out to be difficult to *test* oxygen sensors faithfully.

Sure, you can heat them up and look for a voltage, but after trying that, I
gave up because a "really bad" oxygen sensor has its own code, but a
"slightly bad" oxygen sensor seems to, in my humble experience on two
different vehicles, cause one of two different related codes.

That is, in my experience,
a. A slightly bad lambda sensor can cause a CAT register to never set
b. A alightly bad lambda sensor can cause a "slow response" code

Given that the heat:voltage test of an oxygen sensor isn't really all that
accurate for those two things, and given that oxygen sensors are not only
relatively cheap but also known to not last more than about 100K miles, I
decided on all three vehicles to just "throw the part" at the vehicle.

In the case of the neighbor's CAT register that wouldn't set, it worked.
http://www.bild.me/bild.php?file=5366040sensorwiring01.jpg

The neighbor's kid's Mitsubishi is in testing.
http://www.bild.me/bild.php?file=6815290denso_mitsubishi_02_sensor.jp g

I'm still working on the bimmer (having just this week replaced the two
front Bosch upstrem lambda sensors).
http://www.bild.me/bild.php?file=3533947bosch_o2_sensor.jpg

What's amazing, to me, is that I've never replaced an oxygen sensor before,
in my entire life, but I never worked on such old cars either (two decades
old each of them).

Having zero prior experience with oxygen sensors, I think sometimes,
"throwing parts" at the problem might be OK in the case of emissions codes
because:
a. Oxygen sensors are not permanent parts anyway, and,
b. You have to get past smog (where a ticket is far more expensive), and,
c. You can't really test them accurately (from my experiments anyway).