I am bit confused wiht my 335i, need ur opinios

[ragnar123]

good day folks

So apparently I need a new catalytic converter for my car. The repair and part aren't that cheap and now I'm thinking of getting downpipes instead, so my question is it better to get downpipes cause they seem cheaper? if I do that I don't really need to replace converter at all right? And Do I need a tune before i get downpipes? how exactly it works? thanks

[cochise325]

Will not pass emissions test without the catalyst.

[RocketSurgeon]

The catalyst burns any uncombusted fuel left in the exhaust. You need it to pass inspection. Catalytic converters aren't a common failure, so you might look into why it failed before buying downpipes and a tune. If you have oil leaking from your turbo or valve stem seal, that money will already be spoken for. Generally cats go bad from excessive oil or gasoline in the exhaust, or running leaded race fuel.

[mike@XPH]

good day folks

So apparently I need a new catalytic converter for my car. The repair and part aren't that cheap and now I'm thinking of getting downpipes instead, so my question is it better to get downpipes cause they seem cheaper? if I do that I don't really need to replace converter at all right? And Do I need a tune before i get downpipes? how exactly it works? thanks

Getting catless downpipes will be cheaper.
A tune is not mandatory but it is recommend if you want to take advantage of the higher air flow and make more power.

Aftermarket downpipes will not pass emission.

[AsifLicious]

I agree with what Rocket Surgeon said. Get your car checked out. If everything checks out, I'd go ahead and get the downpipes. They won't pass emissions though