Think Tank: CA "Legal" Headers

[LivesNearCostco]

How does one extend the OEM sensors? I think they have 4 wires each--just splice in 4 wire extensions to each sensor? Or is there an extension cable available at the plug end? I suppose if the cats are only 8" farther down with headers compared to OEM manifolds, the OEM O2 harnesses might work if routed over the transmission, Schmeidman style.

[Hermes]

To me it isn't all that difficult to do, just a matter of money. Find someone with considerable fabrication skills and have them weld in the cats to the headers.

I also don't see why a set of good quality cats directly after the header flanges wouldn't work. Have a shop add the bungs for post cat 02 sensors and extend the OEM sensors to fit. It really isn't that hard and most exhaust shops are not THAT expensive to have them do work like that.

Shad, the problem here is legally exhaust shops are not allowed to do that - fines are huge and/or license revoked. A friend who can weld for you is another story

[derbo]

This is an absurd option.


Hollow out the stock headers (to visually pass with dummy O2 sensors there) and then install cats in section 1 with extended o2 sensors.


Personally most smog shops arent coherent enough to release the cats are downstream from the original location and will most likely just follow the OBDII test. A euro style header + section 1 200CEL cats will most likely keep the OBD sensors happy. I am glad I have a friend who owns a smog shop when the time comes.

[Avetiso]

To me it isn't all that difficult to do, just a matter of money. Find someone with considerable fabrication skills and have them weld in the cats to the headers.

I also don't see why a set of good quality cats directly after the header flanges wouldn't work. Have a shop add the bungs for post cat 02 sensors and extend the OEM sensors to fit. It really isn't that hard and most exhaust shops are not THAT expensive to have them do work like that.

Or you could move to a free state where you aren't fined for flatulence......(sorry, I had to say it)

The question is: would that indeed keep OBDII happy? Reports say that CEL still returns. This idea is my best bet, though, and all other downstream cats that I've seen weren't right after the flanges, but a few inches downstream.

Yeah, CA sucks in that regard. The things they are doing to truckers are far worse, though.

How does one extend the OEM sensors? I think they have 4 wires each--just splice in 4 wire extensions to each sensor? Or is there an extension cable available at the plug end? I suppose if the cats are only 8" farther down with headers compared to OEM manifolds, the OEM O2 harnesses might work if routed over the transmission, Schmeidman style.

The OEM sensors reach pretty far with just some re-routing. The only question with this setup is would it eliminate CEL? Pretty sure 400 cell would pass the sniffer, just gotta make sure there are no errors coming along with it.

Shad, the problem here is legally exhaust shops are not allowed to do that - fines are huge and/or license revoked. A friend who can weld for you is another story

Exhaust shops can't do it, but I'm pretty sure you could just find a fab shop to do it. Plenty of those around...

This is an absurd option.


Hollow out the stock headers (to visually pass with dummy O2 sensors there) and then install cats in section 1 with extended o2 sensors.


Personally most smog shops arent coherent enough to release the cats are downstream from the original location and will most likely just follow the OBDII test. A euro style header + section 1 200CEL cats will most likely keep the OBD sensors happy. I am glad I have a friend who owns a smog shop when the time comes.

Not as absurd as you might think. I actually had a local shop recommend a "cell delete," which I assume means destroy the innards of the cats. Would you net the same gains, though? Pretty sure the SS reps are better for power by design, as well, not simply for the lack of cats.

[derbo]

The hollow cats would be fine, but the CEL would ignite once it realizes the post-02 sensor is reading all sorts of different readings. You would need the post cats in section 1 to get rid of the CEL without a modification to the DME unit.

[Avetiso]

The hollow cats would be fine, but the CEL would ignite once it realizes the post-02 sensor is reading all sorts of different readings. You would need the post cats in section 1 to get rid of the CEL without a modification to the DME unit.

That's what I'm proposing. I'd put them in right after the headers end.

[derbo]

Honestly by design, its going to be terrible. The only thing I can think of is hiding the fact its a true SS header with fake cat covers on it.



How you will do that, is beyond me.

[Avetiso]

Honestly by design, its going to be terrible. The only thing I can think of is hiding the fact its a true SS header with fake cat covers on it.



How you will do that, is beyond me.

I honestly don't think a lot of the techs are smart enough to figure it out. If you paint both the headers and cats with high temp flat black, or get them coated, you could probably make it look stock enough for someone to pass you, so long as the car passed the sniffer and OBDII. It all depends on visuals...

[Smolck]

I wish I had taken pictures of the way the stock manifold goes from the three exhaust port pipes to the cats. The pipes are crimped as it is, but did you know that the "collector" which is just before the pipe gets larger for the cat is a whopping 1"? That means your exhaust for all three cylinders has to flow through a 1" diameter pipe and then into the cats. The fact that our cars make 235hp this way is just insane. And it is clearly why headers open them up and offer huge gains, especially on the ZHP with the bigger cams. No, gutting the stock cats won't do jack.

I didn't think about the fact that CA muffler shops probably have to go through a TON of red tape to work on stock cars, let alone modifieds. Around here, just about any muffler shop I roll into will do anything I ask.

I guess the option really is to find a welder/fabber and pay him on the side. I have also seen these on ebay, might be worth a shot if one of you have $600.

http://www.ebay.com/itm/STAINLESS-HE...5c0302&vxp=mtr

It would be bolt on, and the cats have bungs for the 02 sensors. Might just work.....

[Avetiso]

I can easily find a fabber if my dad doesn't feel like helping me. He never approves of me modding my car, so w/e. Plenty of Russians that'll work for me for cheap.

My biggest concern is this: will having the cats RIGHT after the headers and the O2 bungs welded in right after the cats throw a CEL? That's what I want to know. IF it doesn't, then voila, we have a working solution to make headers in CA, barring visual inspection. 400 cell should pass sniffer, as well.

Any ideas on whether or not it will throw a CEL with that setup?