Cat stolen lambda sensor high emissions

[Bobochops]

Hello everyone, I recently had my cat stolen and replaced by my insurer. I just barely passed the mot emission test on the lambda sensor 1.040 first run and luckily 1.030 on the second which is the limit allowed. (CO 0.01 and HC 0) Does anybody think this joint is dodgy? It looks like fractured metal packed with paste to me?
Also, does anybody have any advice on how to protect the replacement cat? I’ve heard about welding it with chain or braided steel cable, but would the thieving b£@&ard! bother again as its not a genuine honda part?
Any advice greatly appreciated.

[trebor1652]

There is a thread "thieves stole my catalytic converter" that goes into some detail on a way of trying to protect your new cat.
The b!?t*!ds that stole yours will be back, it doesn't matter to them whether it's oem or a n other it still contains the same prescious metals.
Garage the car if you can.

Sent from my moto g(6) using Tapatalk

[sparky Paul]

Looks like dull grey, messy mig welds, from what I can see. Which bit in particular is bothering you?

High lambda is usually an exhaust leak somewhere. If they reused the old mid and tail parts, make sure they haven't disturbed or damaged the joint near the back box by tugging it about, and check the condition of the back box.

[Bobochops]

Thanks for your replies. I think Paul has hit the nail on the head - my back box looks quite badly corroded along the seam and if you zoom in that might be a hole starting on top. It’s the dark grey metal around the lightwr grey weld that was bothering me, I know nothing about welding but assumed these sensors screwed into the cat. This looks like they broke the inlet and then welded the big hole they made shut over the thread of the sensor, but from what you say its the back box not this ugly weld that is the problem.

I will try to find that thread - a picture really does paint a thousand words - the size of chain to use and where to weld are what I need to find.

Thanks again