223whp & 207tq - 986 Forum - The Community for Porsche Boxster & Cayman Owners

BYprodriver · 01-12-2013, 02:38 PM

Quote:

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 · 01-12-2013, 03:44 PM

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 · 01-15-2013, 10:05 AM

Quote:

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 · 01-15-2013, 11:03 AM

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 · 01-15-2013, 02:42 PM

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.

Hawkeye71 · 01-15-2013, 02:47 PM

On a side note, coated pipes and headers are great on boosted cars as they keep the heat in the pipes and help a large turbo spool a little faster. Not really seen much of a gain in power with them on a NA car. But they should help with the heat up of the O2 as the coating will help to slow the dissipation of heat threw the SS pipes.

sgt brad · 01-15-2013, 03:16 PM

Quote:

Originally Posted by 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.

I had planned to use the universal sensor, but have read some problems on Porsches. I don't know how true they are, but its only 100.00 ea for the bosch plug and play ones that are boxster specific. I can't imagine the heater issue being a big concern, but I am trying to cover all of the bases.

sgt brad · 02-06-2013, 07:20 PM

Update...new sensors in and ecu reset. Lasted 200 miles and cel came on. Codes are p1119 and p0154. I am thinking that the right side front sensor wasn't plugged in securely and came loose. I am going to have it on the lift this Friday, but was going to see what y'all have to say. Any thoughts? Does my idea have merit or am I looking at the proverbial o2sensor merry go round?

jaykay · 05-23-2013, 06:46 AM

Quote:

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 · 05-23-2013, 08:21 AM

Quote:

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.