991.2 Carrera Cobb Tuning issue
02-04-2019, 10:10 PM
#76
Former Vendor
Being DIT does anyone know if the there is enough valve overlap to effect AFR readings? Some DIT cars read leaner than actual since you're pushing a certain amount of air (without fuel) through the cylinder and into the exhaust. In short, DIT cars can have an offset AFR reading due to air being added to the exhaust depending on how much valve overlap there is.
On the exhaust, there are several variants. Non-PSE cars have valves too depending on the trim. Our 991.2 4S non-PSE exhaust definitely has valves that activate in 'sport' mode.
On the exhaust, there are several variants. Non-PSE cars have valves too depending on the trim. Our 991.2 4S non-PSE exhaust definitely has valves that activate in 'sport' mode.
02-04-2019, 10:17 PM
#77
Rennlist Member
Being DIT does anyone know if the there is enough valve overlap to effect AFR readings? Some DIT cars read leaner than actual since you're pushing a certain amount of air (without fuel) through the cylinder and into the exhaust. In short, DIT cars can have an offset AFR reading due to air being added to the exhaust depending on how much valve overlap there is.
On the exhaust, there are several variants. Non-PSE cars have valves too depending on the trim. Our 991.2 4S non-PSE exhaust definitely has valves that activate in 'sport' mode.
On the exhaust, there are several variants. Non-PSE cars have valves too depending on the trim. Our 991.2 4S non-PSE exhaust definitely has valves that activate in 'sport' mode.
Regarding the valve, I know what you mean with the non-PSE cars. But from my memory of when I installed my exhaust, that valve wasn't directly connected to the CAT structure (for the non-pse cars at least).
02-14-2019, 03:14 PM
#82
02-14-2019, 04:00 PM
#84
Correct, from added tq/hp, causing pdk slip, I’m wondering does only Porsche have ability to relearn pdk?
i remember in other pdk Cobb APs you were able to go into the troubleshooting tab and perform a pdk service for relearn.
i remember in other pdk Cobb APs you were able to go into the troubleshooting tab and perform a pdk service for relearn.
02-15-2019, 12:45 AM
#85
Rennlist Member
When it comes to cats the only variant is PSE. Otherwise all trims use the same ones.
All of the part numbers that end in X are remanufactured.
So you have left and right without PSE. Then left and right with PSE. Then X versions of all 4 which are remanufactured.
So a PSE cat from a base or S is also used on GTS
All of the part numbers that end in X are remanufactured.
So you have left and right without PSE. Then left and right with PSE. Then X versions of all 4 which are remanufactured.
So a PSE cat from a base or S is also used on GTS
05-17-2019, 01:35 PM
#86
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I just found this thread and i'm glad i did. I have the same exact problem.
installed the tune and i'm not getting any increased power. actually feels slower then stock!!!!
I've been working with COBB as well and they have a great support team for the 991.2's. I've already looked through all my hoses and clamps.
i guess i'll try the cat swap next.
installed the tune and i'm not getting any increased power. actually feels slower then stock!!!!
I've been working with COBB as well and they have a great support team for the 991.2's. I've already looked through all my hoses and clamps.
i guess i'll try the cat swap next.
05-17-2019, 03:21 PM
#87
Yep. Swap the cats and mine worked as it should. Took me months to figure out. I had it in various shops looking for boost leaks and I spent hours myself looking too...
05-17-2019, 04:22 PM
#89
Long story short, this was just my findings... but I thought the car had a boost leak, wouldn’t build boost, installed cat bypass pipes and car ran perfect. I’m assuming the base carrera stock cat couldnt keep up with the extra exhaust flow? Not sure. But it fixed my issue, I also have 30k on my 2017 991.2
05-17-2019, 04:23 PM
#90
I just found this thread and i'm glad i did. I have the same exact problem.
installed the tune and i'm not getting any increased power. actually feels slower then stock!!!!
I've been working with COBB as well and they have a great support team for the 991.2's. I've already looked through all my hoses and clamps.
i guess i'll try the cat swap next.
installed the tune and i'm not getting any increased power. actually feels slower then stock!!!!
I've been working with COBB as well and they have a great support team for the 991.2's. I've already looked through all my hoses and clamps.
i guess i'll try the cat swap next.