xc90 cat efficiency code, only when warm outside?

[ryley999]

Hello everyone! i am a new member, thank you for the add

i have been reading these forums ALOT and have been SUPER helpful, i really appreciate all the help everyone put in here

so i drive an 09 xc90 3.2, and for the past couple months ive had a cat efficiency code for bank 1, and i have just ignored it as our province had scrapped the emission testing. i was just going to put a O2 fouler in to turn off the cel and call it a day..

well lately, we have finally been getting some cold weather here in ontario, and once the temperature goes below -10c the light goes out and stays out until the temperature outside goes back up.

this has me confused, is this normal function of a failing cat? or might it be possible that my bank 1 is running rich and the cold weather helps it lean out a bit? or am i just over thinking this?

couple weeks ago when i first noticed this. it was cold out and the cel went out, so i drove for a bit, put my cheap scanner on it and watch the secondary O2 and the cat DID seem to be reacting much better then when i checked it a month ago when wasn't doing much of anything. temp outside went back up light came back on.. now the past couple days here its been -20c ish out and the cel has been off this whole time its been cold.

has anyone dealt with this before? i am wonder if there is something else happening with fuel or ignition that may be causing my cat to not function properly. or this is just normal for a failing cat, i just dont want to put the o2 spacer in and mask another issue that i may have.

i did replace the afr sensor in that bank didnt need to tho, ( shitty scanner displaying wrong data)

thank you everyone in advanced for reading.

[pgill]

Ryley,

I own two 3.2's (Same Engine as your XC90)
- 2010 S80
- 2008 LR2

Based on what I've read the Catalyst efficiency can be affected by the temperature of the engine.

The root cause of this in a 3.2 is likely a broken Thermostat

Based on my two 3.2's and feedback from other's the Thermostat seems to last about 10 years or 100,000 miles

If you haven't changed your Thermostat I would start there.

If you do change it then post here if it was broken and if it fixes the Catalyst code

Good Luck

Paul

For Reference the Thermostat on my S80 was broken

http://www.freel2.com/forum/topic33004.html


On my LR2 it broke after I removed it

http://www.freel2.com/forum/topic32245.html

[ryley999]

Ryley,

I own two 3.2's (Same Engine as your XC90)
- 2010 S80
- 2008 LR2

Based on what I've read the Catalyst efficiency can be affected by the temperature of the engine.

The root cause of this in a 3.2 is likely a broken Thermostat

Based on my two 3.2's and feedback from other's the Thermostat seems to last about 10 years or 100,000 miles

If you haven't changed your Thermostat I would start there.

If you do change it then post here if it was broken and if it fixes the Catalyst code

Good Luck

Paul

For Reference the Thermostat on my S80 was broken

http://www.freel2.com/forum/topic33004.html


On my LR2 it broke after I removed it

http://www.freel2.com/forum/topic32245.html

thank you very much for the info i never would have thought of that.

would it be possible for me to take the thermostat housing off and see if its broken before i order it?
in your one post about the s80 , i see it literally fell apart, were u having any issues with the engine running temp or anything?

[pgill]

For the S80 the Thermostat had failed.

But there was no code set and my S80 doesn't have a temperature gauge.

When I replaced it I thought I was doing preventative maintenance but upon disassembly it was in pieces as you saw from the picture.

If you want to understand how the Thermostat works then look at this link.

viewtopic.php?f=31&t=86205

A mechanic that posts on this Volvo site says that he can remove the Thermostat without removing the manifold, I can't get my hands in there.

If you think that you can get to it then drain the coolant and remove the hose.

If is broke then the thermostat will move when you push on it.

The Land Rover Thermostat is the same as the Volvo Thermostat so I used a Land Rover Thermostat in my Volvo because it was cheaper.

This link shows what I've done on my S80 so far

viewtopic.php?f=31&t=87687


If you do fix the thermostat please let us know

1 - was it broken

2 - did it clear the catalyst code

Good Luck

Paul