VSC on Engine light on CEL on P0420 quick fix

[MVrod]

So after two incidents in a few days of my VSC light and EML/CEL on my IS250 SE-L I decided to investigate, it turns out I had a leak behind the downstream oxygen/lambda sensor this sensor monitors the performance of the catalyst it does not adjust mixture. Due to the ingress of air the sensor picked it up as the catalyst outside of thresholds .

P0420 Catalyst system efficiency below threshold Bank 1 This is the right bank sitting in the drivers seat . Please note it does not matter wether you have LHD or RHD car the Bank1 is always to the right from the drivers seat .

So I removed the broken clamp see pics and shield and found the culprit a crack exactly where the clamp had been , I cleaned the area after removing shield and treated to the Gun Gum exhaust paste a decent smear all around the pipe , then applied the split flexible repair kit , after tightening which forced out the sealer I spread it evenly over the tube it does look a lot neater than the pics show.

I cleared the fault code down and started up very quiet and solid.

I will remove this when I can and weld properly at a later date when a two post lift is available and refit the heat shield.

This P0420 code was the only code it generated and seeing as the car has only done 83k miles the cats should be ok.

I am confident this will last a reasonable time and will give me a breathing space until I can get on a car lift I did this on the floor using a jack and chassis stand .

 

 

[MVrod]

Since this quick repair I have done a proper repair and removed the temporary metal sleeve and made a stainless sleeve and used stainless Mikalor clamps to hold it all togethher it has been very successful and no EML on o codes thrown

[is200 Newbie]

Good job - Is your car a 2008 model

[Britprius]

I had to do an identical repair on my GS450H although there was no fault code. I think it is caused by a reaction between the exhaust tube, and the heat shield being made of different metals.
I used two pieces of stainless tube about 4" long each. I cut them both into two pieces along there length, and slightly off centre to the tube bore. After cleaning the cracked area of loose debris I coated it with exhaust sealer, and using the two slightly larger "C" shaped pieces of cut tube clipped them over the exhaust pipe the edges of the "C" pieces overlapping each other. A couple of Bannely type exhaust clamps completed the job.
I do not envisage having to return to this repair as it is so substantial. Undoubtedly I will probably have to do the same to the passengers side at some time in the future. If the centre section of exhaust gives any real problems I will build a stainless replacement as I did with the rear section.

John

[MVrod]

On 11/2/2019 at 9:36 PM, is200 Newbie said:

Good job - Is your car a 2008 model

2006 model