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jb92563 · 09-22-2015, 11:55 AM

I'm in the same situation, with the P420 code.

I think the first test would be to swap O2 sensors between the 2 banks to verify that its just not failing O2 sensors.

If so then its a cheap fix.

I did have the engine light go out for a few weeks and then it came back on so it must be borderline.

I just want to get through my Nov smog so I have another 2 years to consider options.

There is a universal Magnaflow Catalytic converter (~$190) to weld on but it would have to be after the header and have O2 bungs welded in as well and remove the 2nd cats to make room. Probably would not pass a visual inspection during smog testing.

The new headers would be ~$1800 each side as a last resort.

09-22-2015, 11:55 AM	#4
jb92563 Registered User Join Date: Apr 2012 Location: Riverside, CA Posts: 1,665	I'm in the same situation, with the P420 code. I think the first test would be to swap O2 sensors between the 2 banks to verify that its just not failing O2 sensors. If so then its a cheap fix. I did have the engine light go out for a few weeks and then it came back on so it must be borderline. I just want to get through my Nov smog so I have another 2 years to consider options. There is a universal Magnaflow Catalytic converter (~$190) to weld on but it would have to be after the header and have O2 bungs welded in as well and remove the 2nd cats to make room. Probably would not pass a visual inspection during smog testing. The new headers would be ~$1800 each side as a last resort. __________________ "It broke because it wants to be Upgraded " 2012 Porsche Performance Driving School - SanDiego region 2001 Boxster S, Top Speed muffler, (Fred's) Mini Morimotto Projectors, Tarret UDP, Short Shifter, Touch Screen Dual Din Radio, 03 4 Bow glass Top (DD & Auto-X since May 17,2012)