Catalytic Converter repair / replacement

Catalytic Converter repair / replacement

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S6PNJ

Original Poster:

5,612 posts

296 months

Friday 18th July
quotequote all
Another day, another thread...

I have a crack in the exhaust side of one of my catalytic converters. A quick phone round to a few places near me for welding services and it seems I might be looking at circa £100 for a repair, so at that price, it's probably worth going for a replacement cat - ebay sell 'approved' (ie post 2001) cats for £112.

My car is Jan 02 (registration date), so past Mar 2001, thus I don't think I can fit a non-approved type (which would only save about £5 anyway). Does anyone have any recent experience of replacing cats? I'm not going down the de-cat route and it needs to be MOT compliant, not relying on 'friendly' MOT places.

Is there anything I need to be aware of with 'mis-matched' cats on the speed 6 engine? Does it make any difference if they are different types / ages etc?
Cheers!

David 99

21 posts

Friday 18th July
quotequote all
Won't it be total rubbish at that price? The ones from Motaclan are nearly £500.

If you look at the Cats2U site, they sell two cats, both from BM catalysts as being compatible. CBM 91115 is £123.92 inc vat and 9115H is £485.09.

Too cheap is too cheap surely?


S6PNJ

Original Poster:

5,612 posts

296 months

Friday 18th July
quotequote all
From eBay, it's a BM cat I'm looking at - https://www.ebay.co.uk/itm/256635326413

Not knowing, hence asking the question.

David 99

21 posts

Friday 18th July
quotequote all
That's the cheap 9115 that I mentioned. It will be cheap for a reason surely? The same company sells one at nearly 4 times the price. There has to be a reason.

A BM cat for a 1.0 Citroen C1 with 68 bhp is about the same price. Does this cat have enough cells in it to work? Will it cause back pressure and loss of performance?

S6PNJ

Original Poster:

5,612 posts

296 months

Friday 18th July
quotequote all
Not knowing, hence asking the question.

mk1fan

10,769 posts

240 months

Friday 18th July
quotequote all
You need to match the outward spigot to your exhaust system. The spigots are either 2&1/8-inches or 2&1/4-inches.

The manifold connection is the same across the board.

Don't rely on what TVR 'should' have fitted to your car. Measure the pipe.

Lambda sensors (one on each manifold) are before the CATs so having one new and one old CAT won't effect running.

I have two used factory items with 2&1/8-inch outlets sitting in my store. They are due to go to the scrap man on my next weighing run. One has started to breakdown but the other is fine. Both were ceramic coated by Performance 1. Send me message if you're interested. I fitted some loverly Clive F 4-inch sport CATs.

Basil Brush

5,347 posts

278 months

Friday 18th July
quotequote all
I use cheap ebay cats for MOT purposes but I wouldn't be running the car with them left in. They are pretty flimsy and one bit sucked back into the engine could mean rebuild time.