223whp & 207tq

[BYprodriver]

Originally Posted by sgt brad

Well good news and bad. Good news first. Headers, bypass pipes and BB muffler is only loud when you romp on it and all resonance/drone is gone. Mark, the previous owner had considered reinstalling the factory muffler bc of the drone. It's all gone. Car actually sounds quieter inside! Wife says its pretty loud when I passed her but that was accelerating past 5k rpms. I am more than happy with the sound.

Bad news...had to install both sets of the max speed mini cats. The front 02 sensor wiring wasn't long enough to reach. So now the 02 sensors are both reading the same and I have a cel. I guess I need to extend the wires or else get a 90 adapter. My only fear with an adapter is that the 02 sensor will be too far out if the 02 stream to read correctly. Right now I imagine its running in strictly open loop mode.

Advice?

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.

[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

[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