Jump to content

Oxygen sensor issue Ho2S DTC P0032

Recommended Posts


I have a 2004 Forester XT 2.0 non turbo, automatic, normally aspirated 

After driving 500 miles across France stopping only for the channel tunnel and to refuel, the engine light came on when the cruise control kicked down  to 3rd at 80mph on a hill. It did this quite a few times and I usually manage to disengage cruise before it kicks down. 

We drove 25Km to the next services and pulled in. We still had 300 miles left to go and rather than calling international recovery we decided to continue to our destination. We arrived without further incident but I limited speed to around 60mph. The last 40Kms was up a mountain pass road in 3rd gear.

Other than the engine fault light lit, I haven't noticed anything unusual. Fuel economy performance, lack of exhaust smoke, all seem much the same . The engine starts from cold without issue. 

I bought a ODBII reader and it revealed a P0032 actual and the same code pending (Heated oxygen sensor (HO2S) 1, bank 1, heater control -circuit high). These faults reoccur after deleting them after a couple of minutes with the engine running.

What  is the purpose of this sensor? isn't the engine is normally aspirated with fuel-air ratio determined by carb jets / needle valve?

We're 1000 miles from home. Should we risk the return journey with the engine light on?

Thanks for any suggestions.





Link to comment
Share on other sites

Yes that not a big issue, get it fixed once back .

Probably heater element in O2 sensor pre cat failed or wiring/connector at sensor .

You have pre cat and post cat sensors which monitor cat function and engine fine control fueling (fuel injection)


Link to comment
Share on other sites

What  is the purpose of this sensor?


purely to send mV readings from the exhaust gas  to the EC module which as MrB says govern the rich/lean fuel settings.

a u/s one can cause all sorts of erractic running/idling and high fuel use amongst other things.


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...