Where to get a catalytic converter? (5g 2.2VTI)

chris_rd92 · Post by **chris_rd92** » Mon Mar 04, 2024 12:27 am

Hi guys,

So after 5 years of solid daily driving, the exhaust on my 5th gen BB8 has inevitably developed a low rpm rattle which I am almost certain is the catalytic converter breaking down.

I seem to remember reading that these are now discontinued. I've seen a few suspiciously cheap one floating around on various websites, and also Rockauto have a good selection, but just thought I'd see where everyone else I sourcing them from? Would I be better off getting a second hand genuine oem one if I can?

Car is a 97 2.2VTI BB8.

Cheers
Chris

Post by **Drax** » Mon Mar 04, 2024 9:03 am

https://www.cats2u.co.uk/

i know lots of people who have used these, they seem very good. make sure you get your specific model in the choice menu though

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Mon Mar 04, 2024 11:24 am

Second hand oem would be better for sure - the oem cats are always the best quality - but I've fitted a cat/pipe system made by BM Catalysts (who supplies the ones through where Drax linked) to my C5 and it was good quality. Fitted up perfectly and it's lasting well so far.
So another recommendation from me, there.

PamThePrelude21 · Post by **PamThePrelude21** » Mon Mar 04, 2024 10:02 pm

not really an off the shelf choice but a 200 Cell universal cat will pass mot still and make the exhaust a bit of a deeper tone, i had a friend weld mine up for me i know these have a lot of size differences unless you get a cat from an identical age/engine prelude.
if you know a good exhaust shop or friend with a welder its a good option and fairly budget for whats on the market mine only cost 200 in materials plus a few beers for my mate

Scott560 · Post by **Scott560** » Tue Mar 05, 2024 9:05 am

I'm pretty sure I fitted a cheapy cat to my h22a5 lude after the original melted after a track day. it passed emissions fine afterwards.

Since the cars are old and tax is not based on measured emissions, you are lucky that you do not need to purchase a type approved cat.

I think there are 2 or 3 different shape/length cats. H22a5 has one length, and later models have longer or shorter ones (h22a8). I seem to recall that you can tell from the offset of the flanges, but appreciate it is hard to check this when its fitted to the car!

nalla · Post by **nalla** » Wed Mar 06, 2024 6:42 pm

Hi,
I have a spare original jdm cat, is welded to 3” stainless steel pipe.
Understand it maybe a different size to ukdm.

Can measure if need be..

chris_rd92 · Post by **chris_rd92** » Wed Mar 13, 2024 1:59 pm

Thanks for the help everyone! So before ordering anything I really want to know for sure what the issue is, so today during my lunch break at work I found 20 mins to quickly jack the car up to have a nose around. Unfortunately I didn't have access to any jack stands so the most I could do was reach under with the jack handle to give everything a prod, as I wasn't comfortable going fully underneath without out them.

Strangely if I hit the cat with the jack handle I couldn't get it to rattle, but if I hit the rubber exhaust hanger holding the downpipe/flexi in place then it rattled just like what could hear while driving.

I've had a chat with the Subaru specialists next door to my work and they have said they can get the car up on their lifts next week to have a proper look for me.

Side note, I have noticed that in the rain I'm getting quite a bit of steam from the bonnet as the rain water evaporates off, could this be an indication of a blocked cat causing the manifold to get extra hot? Or would I see other symptoms first if that was the case?

Scott560 · Post by **Scott560** » Wed Mar 13, 2024 2:46 pm

Generally if the cat is blocked, you will start to feel driveability issues. Mine happened quite quickly. I drove home from the track day, and within a day or two, I was struggling to get to 50mph, the exhaust was blocked. It was like going uphill or having the handbrake on. If the exhaust/cat is blocked like that, you will get more temperature in the cat, but that wouldn't really translate into extra steam from the engine/bonnet (maybe a little extra from water under the car hitting the exhaust which will be hotter).

Do you have the manifold heatshield? I do get a little bit of evaporation from the bonnet if its hot then starts raining and then stops but generally nothing of note.

The garage can confirm if the cat is breaking up, but there isn't really a test for it being blocked (unless its so blocked it reduces power or gets very very hot)

chris_rd92 · Post by **chris_rd92** » Wed Mar 13, 2024 2:56 pm

I had a feeling that might be the case, yeah I do still have the heat shield. I'm starting to consider the option of replacing the entire downpipe as well as the cat, however there is a complication here too... A while back I fitted a full powerflow catback system which I got cheap second hand, but it turned out to be for a JDM model, so it was slightly too short to reach my cat. As my downpipe/flexi was a little worse for wear, I decided to have that cut and lengthened instead, which in turn moved my cat further rearwards to meet the powerflow system.

So here is the new question, can I just buy a JDM H22A5 downpipe with a new cat to fit my current exhaust?

Scott560 · Post by **Scott560** » Wed Mar 13, 2024 5:02 pm

My decat wasn't quite the right one for my h22a5 , so when they installed it, they had to sleeve the downpipe so that its length and rotation could be adjusted (handily, so it could be swapped between the 'wrong' decat and a new cat).

If yours has been welded up, it may be that the original system cannot be re-fitted without alterations/welding. Best bet is to just buy the cheap cat, take it to an exhaust place and ask for forgiveness. They can then alter what is needed to make it all fit. When you get to old cars like ours, what has been fitted (or made to fit in the past) you just don't know what is there, so no point trying to guess or worry about making it all fit without cutting/welding.

It may be worth having the downpipe custom made - the ones available online (new) look really badly formed pattern parts and look really restrictive (not mandrel bent). I was lucky I was able to get a replacement second hand downpipe, but they do not pop up very often at all (cheers @arif_manji )