1) Change of exhaust manifold due to small cracks.
2) Change of Turbo due to cracks
3) change of Lambda/O2 sensors
4) Change of Cat / Downpipe
5) replacing of all the seals/gaskets in the relevant areas with original ones.
So currently my T6 consists of a low milage exhaust manifold with 0 cracks with all exhaust manifold studs in place. New/Used turbo with very low milage with 0 cracks. New Lambda/O2 sensors from Denso and with all new seals/gaskets from Volvo.
Yesterday I drove on the Autobahn when it was around 1°C/33°F for quite a while at different speed rainging from 100kph/60mph up to 220kph/136mph. Long 4 hour drive. And after couple stops with shutting the engine and cooling down then turning it back on again the P0420 Catalyst System Low Efficiency Bank 1 came up. I pulled over and deleted the code with a portable OBD reader but the ultimate question comes to my mind.
After my car been through major repair, with everything at the back side of the engine being litterly replaced, I am now wondering if IPD is being truthful with their statement on youtube saying : “that requires no modification”. Sure the downpipe was installed with no modifications even though we had to say goodbye to 2 shielding that used be on the stock cat since there isnt anymore screw holes on this one and also had to make due with a bolt placement on the turbo shielding since original turbo shielding has 1 bolt that also mounts to the original Catalytic convertor but, those thing are fine. The thing is I bought the downpipe to first have an alternative to the factory Cat and also maybe have some slightly improved performance without a tune. I knew i was taking a risk as they emailed to me saying: “there is a possibility that this downpipe will throw a check engine for the rear lambada sensor. or specifically, a catalyst efficiency below threshold. Some cars do and some cars don’t. this is usually due to the higher flowing cat not getting hot enough to satisfy the system. in thes cars the rear lambada sensor can be spaced out to remove this code.”. But after looking on the forum, I got the impression that the spacers also dont really work as some people already tried that.
Also funny thing is, Viva Performance in their website, they say the following: “The metal catalyst included will cause no errors or malfunctions to ensure your vehicle runs and drives perfectly.”
So in conclusion, if you are planning getting the IPD 150cell High flow downpipe, even in a perfect environment like my car where every single component was changed behind the engine bay, it will throw an engine warning light. This could be maybe due to colder weather or high speeds I dont know. But regardless I would suggest be prepared for a tune up.