Anyone Have Headers Installed Without Cats?

[Bfan]

I wanted to avoid a remap so I rerouted the secondary censors to after the secondary cats that are further downstream. I had to lengthen the censor wires by over two feet, and carefully route them away from exhaust heat. I hope keeping the secondary cats will get me through smog test in due time, guess it depends on how strict they are where you live, as removing the primary cats will newer pass visual inspection.
The downstream censors are not vital for the engine management like the upstream ones, but are supposed to trigger CEL if the cats fail. I bought some ½ in stainless steel tubing that is threaded on the inside in a shop that sells hydraulic fittings and welded it to the exhaust, just after the secondary cats to fit the downstream censors.
If I fail the smog test when time comes, I guess I will try new midi tubes with 200 cell sports cat. At least I have no CEL´s so far.

[Johnny Danger]

I've both experimented and written extensively on the topic of exhaust mods for the 986 boxster. Simply installing a set of headers will not only fail to improve performance, it will render the vehicle non OBDII compliant as well. In short, there is no inexpensive way to improve the 986 exhaust system, or get around the issue of a CEL.

[BYprodriver]

Originally Posted by Bfan

I wanted to avoid a remap so I rerouted the secondary censors to after the secondary cats that are further downstream. I had to lengthen the censor wires by over two feet, and carefully route them away from exhaust heat. I hope keeping the secondary cats will get me through smog test in due time, guess it depends on how strict they are where you live, as removing the primary cats will newer pass visual inspection.
The downstream censors are not vital for the engine management like the upstream ones, but are supposed to trigger CEL if the cats fail. I bought some ½ in stainless steel tubing that is threaded on the inside in a shop that sells hydraulic fittings and welded it to the exhaust, just after the secondary cats to fit the downstream censors.
If I fail the smog test when time comes, I guess I will try new midi tubes with 200 cell sports cat. At least I have no CEL´s so far.

I tried this too with Dansk 2ndary sport cats. Car ran great but always had CEL for poor O2 heating.