Magnaflow Universal Catalytic Converter - 986 Forum - The Community for Porsche Boxster & Cayman Owners

hancock1701 · 09-24-2015, 08:16 PM

Hi guys,

So the day I fear most has come (almost). My car is taking forever for the Catalyst Readiness monitor to set, and I need it for my upcoming CA smog test. Observing the oxygen sensor voltages, I can see the bank 2 cat is very unresponsive and slowly dying.

Magnaflow has a universal catalytic convert that is CARB approved for this car. Since the second catalytic converter along the exhaust path (right before the muffler) is not monitored by the computer, since there are only two O2 sensors before and after the pre-cat that is integrated into the exhaust header. I was thinking about finding a shop that can cut that second cat out, weld the universal on in place, then make a hole for the oxygen sensor downstream of the univesrsal cat. Then both the pre-cat and the univesal cat are monitored, and hopefully that makes the computer happy enough to set the Catalyst monitor.

What do you guys think? Or am I crazy? Spending $4000 just for emission purposes on a $8000 car just doesn't make sense to me.

tommy583 · 09-24-2015, 08:51 PM

Why don't you just buy a used header/cat from Woody or ebay? Then it will still look stock for the California emissions police.

thstone · 09-25-2015, 04:14 PM

Quote:

Originally Posted by hancock1701

I was thinking about finding a shop that can cut that second cat out, weld the universal on in place, then make a hole for the oxygen sensor downstream of the univesrsal cat. Then both the pre-cat and the univesal cat are monitored, and hopefully that makes the computer happy enough to set the Catalyst monitor. What do you guys think? Or am I crazy?

I'd suggest a cheap used cat. They will get you thru emissions (worked for me).

mikefocke · 09-25-2015, 04:44 PM

If the cat goes it is almost always the first one, the one monitored. Look up P0430.

Isn't there an obvious modification test to your smog test? Wouldn't a deviation side to side raise concerns? Will the ECU be able to compute the correct AFR with the imbalance? Lots of people have taken their exhausts off and they are just sitting around. Not to mention wrecking yards.

hancock1701 · 09-25-2015, 05:31 PM

Quote:

Originally Posted by thstone

I'd suggest a cheap used cat. They will get you thru emissions (worked for me).

I haven't had any luck finding those around my area (Orange, CA). I'll keep an eye on eBay and Craigslist.

Quote:

Originally Posted by mikefocke

If the cat goes it is almost always the first one, the one monitored. Look up P0430.

Isn't there an obvious modification test to your smog test? Wouldn't a deviation side to side raise concerns? Will the ECU be able to compute the correct AFR with the imbalance? Lots of people have taken their exhausts off and they are just sitting around. Not to mention wrecking yards.

From my understanding, the ECU only use the upstream O2 sensors to calculate the AFR, so whatever downstream of that is for emissions purposes only. I've been driving the car for the past two months and couple thousand miles, it has not set the codes P0420 or P0430, but will not set the Catalyst monitor either. From what I've read, for my model year 2001, during a smog test, they don't measure the tailpipe anymore, just plug it in and read the Readiness monitors.

hancock1701 · 09-25-2015, 05:46 PM

Quote:

Originally Posted by tommy583

Why don't you just buy a used header/cat from Woody or ebay? Then it will still look stock for the California emissions police.

I'm sorry who is Woody?

tommy583 · 09-25-2015, 06:39 PM

He is a member of the forum. His user name is itsnotanova. He has the best used part prices on the internet. I almost can't believe you have never heard of him. He is famous on here

Jager · 09-25-2015, 08:37 PM

If you plan on keeping the car, contact Sunset Porsche for a new catalytic converter... Best price I found. You do not have to do both sides, just the converter that is failing.

BYprodriver · 09-26-2015, 11:10 AM

Quote:

Originally Posted by hancock1701

Hi guys,

So the day I fear most has come (almost). My car is taking forever for the Catalyst Readiness monitor to set, and I need it for my upcoming CA smog test. Observing the oxygen sensor voltages, I can see the bank 2 cat is very unresponsive and slowly dying.

Magnaflow has a universal catalytic convert that is CARB approved for this car. Since the second catalytic converter along the exhaust path (right before the muffler) is not monitored by the computer, since there are only two O2 sensors before and after the pre-cat that is integrated into the exhaust header. I was thinking about finding a shop that can cut that second cat out, weld the universal on in place, then make a hole for the oxygen sensor downstream of the univesrsal cat. Then both the pre-cat and the univesal cat are monitored, and hopefully that makes the computer happy enough to set the Catalyst monitor.

What do you guys think? Or am I crazy? Spending $4000 just for emission purposes on a $8000 car just doesn't make sense to me.

Moving the O2 sensor any further away from the primary (warmup cat) will set the CEL & trouble code for slow warmup of the O2 sensor.
Just get a used part to replace yours.

thom4782 · 09-26-2015, 11:15 AM

So long as your car doesn't have any codes (CEL on or stored) and your emissions system is 'ready' for monitoring, you should pass CA's test. IIRC, CA no longer does a tailpipe test for cars newer than '98. Mine was in this situation and passed with flying colors. BTW: They did do a manual inspection of the system to see if the right equipment was still there.

It's a violation to install a used catalytic converter in CA. That's why it's hard to find a shop willing to do the work or to find one for sale in the junk yards.

If you want to buy a new genuine Porsche one, ECS Tuning sells them on their website. I paid $1675 delivered a couple of months ago for Bank 2 exhaust / converter manifold. Bought it because I was sick of seeing the CEL come on. The other Bank is even cheaper.

BYprodriver · 09-26-2015, 11:27 AM

[QUOTE=thom4782;467783]So long as your car doesn't have any codes (CEL on or stored) and your emissions system is 'ready' for monitoring, you should pass CA's test. IIRC, CA no longer does a tailpipe test for cars newer than '98. Mine was in this situation and passed with flying colors. BTW: They did do a manual inspection of the system to see if the right equipment was still there.

In CA 2000 & newer cars are tested via the OBD2 connector for system readiness codes.

Same year warmup cats located as close to the exhaust ports as possible became mandatory.

Lapister · 09-26-2015, 11:38 AM

i too have to deal with Commiefornia smog police and they are really cracking down on these aftermarket converters. Be aware what you are buying if you go aftermarket as they look for the approved stamp on these. Went through this crap with a toyota recently that stated Carb approved but in reality there is a Calif only Carb approved too. Make sure it's the Ca and not the 49 state Carb. It is true the sniffer machine has gone away now being replaced by newer system that I believe plugs into OBD2 port. I would drive the car after clearing all codes till all the readiness codes are met. Also Calif allows 1 or 2 readiness codes to not be met depending on your year.