ToothDoc

I'm not sure if that would trigger a CEL or not. There is another kind that is an extension like those with a small catalytic converter inside so the secondary O2 actually sees a cat but the rest of the exhaust doens't. In the end, there is more than one way to skin a cat and as long as inspections go fine and I gain the HP, I really dont' mind any solution. I just started thinking about this in light of the CEL I've had recently.

imp0rted1

doc

not sure if you saw the usdm novel header thread.. look at the o2 adapters

90 degree "mechanical fix' type.. also has holes for exhaust restriction.

maybe this is key to success...

Juanca

iTrader: (5)

Lou, I witnessed this race and didn't expect CJ to be so close to Danny. Even though Danny was ahead, he was just walking away, not pulling as hard as I thought for full exhaust plus headers and no cats at all.

Cronic

iTrader: (1)

I would have to imagine PPE or SIKKY would have tested/explored mechanical fixes first, before going the way of the elec. fix. I mean those mechanical fixes have been used on cars for a LONG time.

RCB

iTrader: (18)

^^^^ I am thinking that the A/F sensor only reading off the back cylinders vs. PPE/Sikky collecting the sum of each bank might have something to do with why novel can use this method.

Cronic

iTrader: (1)

Can you expand on that? I can't see how that would effect the rear o2/cat efficiency, but maybe it does.

One thing I can see is how many people(on usdm cars) are actually running Novel headers, and for how long? Who knows if the fix will even work, long term.

RCB

iTrader: (18)

I really don't have a technical explanation. I just see that as the only thing that is differant. Good point about the length of time being used. Maybe it is an assumption that the mechanical fix will work on U.S. cars.

The only other thing I can think of is that maybe the rear cylinder only sampling causes the A/F sensor to see a richer mixture. That might make the ECU lean the mixture out a little which would help get the sample for the rear sensor (which is also pulled away from the exhaust stream)where it needs to be.

That's assuming that the intake manifold design favors the forward cylinders and even at that my idea is a huge stretch. I am really not even subscribing to that theory but more or less just thinking out loud.

imp0rted1

found this on ebay

http://www.ebay.com/itm/O2-Sensor-Bung-90-degree-Catalytic-Converter-NEW-/151275647594?_trksid=p2054897.l4275

listed as "precious metal substrate" so i'm assuming that means the honeycomb is actually a mini cat?

RCB

iTrader: (18)

That would make more sense then it just being an elbow that moves the sensor out of the exhaust flow.