Hello fellows,

I have a recurring P0133. I can't seem to pinpoint what triggers it.
I'll get the code, clear it, and it won't come back for weeks, but then it will show up again - only thrown once, MIL on.

Actron lists the code to mean :
O2 Sensor CKT Slow Response (Bank 1 Sensor 1)

The one thing I can gleam from the freeze frame data is that the engine load percentage is usually low when this is thrown, ~10%.

I know this points to something wrong with the signal from the front O2 sensor, but does anyone actually have any experience with this code recurring this fashion and/or what it might mean? what might cause it?

I know the easy first thing to try would be to replace the O2 sensor, but I'm pretty sure it was replaced at a Volvo indy I bought it from. I also happen to know that this guy doesn't like using generic O2 sensors, though I guess that doesn't guarantee that he didn't use one this time...

The car gets fine gas mileage and has lots of power and otherwise seems to work great.

Any and all ideas are welcome.


--
1998 V70 AWD Turbo 190k+

If the car is otherwise running great, my guess is that it is a gummed up O2 sensor. Even if it was replaced, they sometimes go bad. Basically, you could check all the wiritng to it adn if that all looks good, you're back to an O2 sensor that is occasionally slow to respond, thus throwing the code. If it were me, I'd probably just figure on replacing that oxygen sensor.

It's a bummer that they're so expensive though...

hope this helps,

Nate
--
1997 850, 1979 242GT, 1990 740GL

I had hoped someone might have some advice for me on this, so I'm replying to the original post to bump it up to the top of the list again.

If anyone has had any issues with a P0133 code, please weigh in and let me know what the story is.

I was getting the same code and it was the little vac line that runs behind the manifold there is an elbow there that goes bad and can trigger that code. See top pic at the link below.

http://volvospeed.com/Repair/vacuum_lines.php

I found the elbow after replacing the airmas meter and front o2 sensor.
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1998 v70 GLT AWD