2011 XC90 3.2, Coil failure followed by p0420 & p0430

[davido2019]

My XC90 has 211,000mi and currently has the p0420 & p0430 codes set. This problem started when the coil for cyl #2 experienced a meltdown. Three miles from the house I limped home but I know now I should have pulled over and shut the engine down. That week I replaced all coils and spark plugs with new Volvo parts and the vehicle drives fine but these codes will not clear. I have cleared the codes with my scan tool but they both immediately return. Im trying to determine which part(s) have been damaged and need to be replaced. I have the Innova 3040a scan tool and also have VIDA if there are readings I should monitor for clues. Would the main catalytic converter be the most likely damaged part/cause. Regardless of the part(s) damaged i plan to fix and drive this vehicle to 300k and will post the ultimate fix to the problem. Thanks for any assistance.

[RickHaleParker]

P0420 & P0430 are Catalytic Converter Efficiency. Anything that messes with the Air/Fuel ratio or the burn efficiency can trip them codes.

Did you use OEM coils?
Did you replace the plugs?
Air leaks?
Exhaust leaks

[davido2019]

Thx Rick. Replaced all six coils and six plugs with genuine volvo parts. I will check for intake and exhaust leaks.

[Masscomguru]

With the bad coil, unburned fuel was just dumping down to the cat. Some distance with highway speeds would burn off any residual gunk. That being said, these codes are supposed to require two drive cycles to trigger the SEL. So if the codes are immediately coming back, they are either not being fully cleared or there are bad o2 sensors. Have you cleared these codes with vida?

[pgill]

Davido,

Have you replaced your thermostat?

There is some evidence that a failed Thermostat may lead to a coil pack failure.

If you want to understand how the P0420 and P0430 codes are set then take a look at this document

MY07B6324S-S80XC90AWD.pdf

Also what spark plug part number are you using?

My neighbor was having a catalyst efficiency problem on his Toyota and I fixed with with Denso Iridium TT plugs.

And a friend of mine is running the Denso TT plugs in his 3.2 (with over 200,000 miles) and it is running great no codes.

The stock plugs are Denso Iridium but not the TT (Twin Tip)

Good Luck

Paul

[RickHaleParker]

The stock plugs are Denso Iridium but not the TT (Twin Tip)

Denso does not have any ignition parts for the 2011 3.2 per the Denso parts finder..

Bosch has the Double Iridium Pin-To-Pin, Part Number 9615.

[pgill]

The stock plugs are Denso Iridium but not the TT (Twin Tip)

Denso does not have any ignition parts for the 2011 3.2 per the Denso parts finder..

Bosch has the Double Iridium Pin-To-Pin, Part Number 9615.

Rick,

You are 100% correct Denso doesn't list spark-plugs for a 2011 or 2012 XC90 3.2

Using the Denso site and looking up the cross reference for the BOSCH 9615 shows the following results

Denso 5344 IKH20 Iridium Power - single fine tip (This is what I use for both of my 3.2's a 2008 and a 2010)

or

Denso 4704 IKH20TT Iridium TT - twin tip (This is what my friend is using and what I will be switching to when I change plugs next)


It is interesting that Denso doesn't list the 5344 or 4704 for the 2011 XC90

For reference Denso does show the following (Iridium Spark-Plugs) for the XC90 3.2

2008 5344 4704 3421
2009 5344 4704 3421
2010 5344 4704 3421
2011 none
2012 none
2013 5344 4704 3426

The interesting thing to note is the switch in 2013 to the 3426

The 3426 is a twin tip Iridium spark plug.

Denso calls it a SIP (super ignition plug)

The gap for the 3426 is .044" which is even larger than the gap for the 4704.


Maybe my next set of spark-plugs will be 3426 instead of 4704


Take care


Paul

[oragex]

See as above, your thermostat is critical and causes engine overheating on the 3.2 which can also explain a sudden coil failure. If it's the original one, time to swap it. As for the catalytic convertor, 3 miles drive is not that bad - unless the road is going uphill then it can be problematic (always keep some tools and disconnect the injector on that cylinder right away - youtube shows how to locate the cylinder). Don't rush into replacing the cat as yet, even if it was damaged, it may 'recover' after a while, or at least you don't have a Check Engine yet so it's not that bad unless you need to pass emissions.