223whp & 207tq

[sgt brad]

Originally Posted by BYprodriver

See if the rear O2 sensors are long enough to work in the front, they should. If so you may want to get new rears & install in the front. You may get a CEL for slow heating of the O2's so keep in mind to minimize that.

Thanks pro. I usually do my own work but things are so hectic with work lately that I just have to pay someone else at this point. If the rear o2 sensors are longer then that seems like an easy fix. What's the worry over the heater? Would I be better served to try something different? My mechanic was able to make it work with the 90 degree max speed mini cat so the distance is probably about 2".

[sgt brad]

Here is what I have right now. You can see the mini cats. My thought right now is to take the downstream mini cats out of the header and switch the connections for the 02 sensors. Essentially the downstream sensor would be read as the upstream sensor, while vice versa would be true. By pulling the mini cat out downstream, The upstream 02 sensor would be reading out of the collector rather than the primary tube. Would this work?

[sgt brad]

Would this work and make life easy? Just extend the first sensors?

RX-O2EXT

[BYprodriver]

Originally Posted by sgt brad

Here is what I have right now. You can see the mini cats. My thought right now is to take the downstream mini cats out of the header and switch the connections for the 02 sensors. Essentially the downstream sensor would be read as the upstream sensor, while vice versa would be true. By pulling the mini cat out downstream, The upstream 02 sensor would be reading out of the collector rather than the primary tube. Would this work?

I only see 1 O2 bung in the pic, but the rear O2 wire is about 5" longer than the front O2. Ideally you try the rears in the front bung & if they reach just buy 2 new rear O2's to use in the front & use the old rear O2's in the rear with the "mini cats". If the O2's don't get to operating temp quick enough for the DME it lites the CEL & logs a P code.

[sgt brad]

Thanks again for the reply pro driver. Is it ok to buy the bosch o2 sensors? Porsche and pelican are awfully high on these only to find out I have another fault due to the slow heating. Darn I didn't see any of this coming.

Ps. Look slightly up and to the left of the "obvious" o2 sensor and you see the block like piece? That's the max speed 90 degree sensor.

[BYprodriver]

Originally Posted by sgt brad

Thanks again for the reply pro driver. Is it ok to buy the bosch o2 sensors? Porsche and pelican are awfully high on these only to find out I have another fault due to the slow heating. Darn I didn't see any of this coming.

Ps. Look slightly up and to the left of the "obvious" o2 sensor and you see the block like piece? That's the max speed 90 degree sensor.

I use the Bosche 15182 front & I think the rear is 15183. 996 same year is even longer leads if you need longer. I think the only way to avoid the heating CEL is the put the front O2 bung closer to the exhaust port, OR the new route I am trying, NHP sport cats with Fabspeed secondarys ceramic coated inside & out.

[sgt brad]

prodriver, thanks again. i was about to order the secondary sensors part#15183 when i read your post. i'd like to see what the length is on the 996 pre-cat sensors, but the bosch part number i find is 17044. this is listed as a 5 wire sensor and the connector looks different than the boxster one from the images i've seen. the lengths of the pre vs. post cat bosch sensors for the boxster are 245mm front and 405mm post-cat. realistically all i need is a 300-325mm length. if the 996 front sensor is closer to 300mm then it would likely eliminate the risk of heater p codes. do you have a part # that i can reference? fwiw i am going to ceramic coat the headers if they are shown to give gains. i also may end up having to relocate a sensor bung further up into the primaries, but would rather not if i can just find an appropriate sensor. thanks.

brad

[Hawkeye71]

sgt brad, I went with the top speed header back set up on my 2000 2.7. (headers, cat deletes and mufflers). I am in the process of lengthening the O2 wiring.

From my experience with Bosche O2's a 5 wire is a wide band unit while a 4 wire is not. I've used the 5 wire in some of the turbo cars I've built in the past in order to log the air fuel to tune AEM and other stand alone ecu's with.

Bosche also make "universal" 4 wire O2's that come with a good length of wire that I might give a try. You just connect your plug to the new O2 wire with the supplied splice connector. I've used them in everything from BMW's to Honda's with great success.

Partsgeek.com has them for the up and down stream for most years boxsters. Prices are $44-$64.

[jaykay]

Originally Posted by BYprodriver

I only see 1 O2 bung in the pic, but the rear O2 wire is about 5" longer than the front O2. Ideally you try the rears in the front bung & if they reach just buy 2 new rear O2's to use in the front & use the old rear O2's in the rear with the "mini cats". If the O2's don't get to operating temp quick enough for the DME it lites the CEL & logs a P code.

Would this mean moving the catalyst elements out of the header and to the secondary pipe section would result in improper heating time?

I was thinking about straight headers and Fabspeed cats in front of the muffler would give a better exhaust flow set up.

This would involve putting in long o2 sensor wires and shielding them from heat.

Has anyone successfully accomplished this without getting coded

[BYprodriver]

Originally Posted by jaykay

Would this mean moving the catalyst elements out of the header and to the secondary pipe section would result in improper heating time?

I was thinking about straight headers and Fabspeed cats in front of the muffler would give a better exhaust flow set up.

This would involve putting in long o2 sensor wires and shielding them from heat.

Has anyone successfully accomplished this without getting coded

I have with Dansk sport cat secondarys & everything ceramic coated. Car ran great, but O2 heating & AFR P codes.

[jaykay]

Thanks you saved me a lot grief..... like your set up. What did you pay for your headers?

I ceramic coated my muffller as well

[BYprodriver]

Originally Posted by jaykay

Thanks you saved me a lot grief..... like your set up. What did you pay for your headers?

I ceramic coated my muffller as well

That was my 3.2 exhaust setup. Current 3.6 exhaust is in post 26.