[Gemballa1980]

While I’m aware that Catless DP’s aren’t meant for street, most still seem to use them. Also the likelihood of the RTA stopping you and getting under your car is pretty slim. I’m assuming the only situation that would have you concerned with running them would be if you have to roll over the pits / car inspection.

This brings me to under bonnet mods. In some states, DCI’s and BOV’s are illegal and the likelihood of being stopped and having the RTA look under the bonnet is obviously higher. We could bring meth into this too, but it doesn’t seem to be as common in Aus.

My concern: If you’re stopped and found to have DCI’s and/or a BOV, in addition to a fine, it’ll likely lead on to a full inspection too. This could lead to the discovery of catless DP’s – no?

So now I’m thinking, would one be better off with a drop-in filter and DV’s instead of DCI and bov, as they would decrease the chance of being pinged should the RTA pop your bonnet. And secondly (probably a stupid question) if you were ordered to have a full inspection, would you remove the catless dp’s prior – given how much of a PITA they are to remove.

This sort of leads onto a side question; since 335i's run dual cats (primary and secondary) – is anyone aware of the ruling with only running secondary? Are we able to run bigger cats in place of the secondaries, or it doesn’t work like that? I remember reading somewhere that an ADR approved cat would be legal, so it the secondary cat ADR approved??

Just after your thoughts and/or experiences.

Thanks!