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Just looking at the pictures of the de-cat pipes s4-99 has fitted in the "custom exhaust" thread. I had the same set-up made while I had the rest of my system made, so main cats removed getting ready for more power in the future, straight through pipe after the flexy joints then centre and rear box after, seemed easy to have it done at the same time as some pipework was going rotten, however I still have the pre-cats at the moment.

My question is how will it fair come MOT time, emissions wise? Will it pass ok, guess it'll be best being up to running temp to start with?

I have a re-mapped ecu fitted, but I also have the standard ecu, will I be better off refitting the standard one?

Thanks in advance to all.

regardless of what ECUs you have, if your car is totally decatted, it will NOT pass any MOT

S2tuner wrote:regardless of what ECUs you have, if your car is totally decatted, it will NOT pass any MOT

I think he's asking if it will pass an MOT with just the pre-cats???

I dont think it will with just pre-cats, but i'm sure other member's will confirm.....

It will pass with just precats, but ideally you want to get rid of the precats and keep the main cats on, turbos like that much better )

As long as it passes for now I'm happy, MOT is soon. I know it's not the ideal set-up, but it'll do me for the time being, was just easier and cheaper at the time this way round as the cat side of the flexi was rotting through. Can't do any harm for now? Prob swap for some bigger downpipes with just hi-flow main cats in the future.

get rid of all the cats and find a freindly mot center

jimbo1234567 wrote:get rid of all the cats and find a freindly mot center

2nd that.....

I've tried! No one round here will budge, bloody VOSA computerised tests, got away with it for years previously on various decatted cars, but no one local will do it anymore.

where abouts are you?

So if you remove the precats and leave the main cats on will it still pass the MOT...

Thanks

Andy

yes

You could get your main cats made up so you can slip them on for the MOT then slip them off when it's done. Hour's work each swap, so gotta be worth 2 hours of your time for the reward

Thanks for that...

It was just that i was enquiring today about a new powerflow exhaust for my 1999 pre-face lift s4... £580

I will be going down this road... using my cats as a spare for MOT time...

Thanks guys...

Andy

That price is for a full system from the flexi pipes back i take it, and your cats made up to fit on & off?

jimbo1234567 wrote:where abouts are you?

I'm in Stamford, near Peterborough.

And I no longer ave the main cats, bugger.