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Discussion summary
YOUR RESEARCHFabSpeed X Flow 200c Cats
Reported or suspected cause
very strange and we have not seen it
Reported cause
No successful repair reported for this finding.
1
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0
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Read evidence and context
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Reported cause
This issue is very strange and we have not seen it before.
Leading evidence: 'very strange and we have not seen it' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'very strange and we have not seen it' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check fabspeed xcats' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
Checked for leaks and found both clamps, from the OEM Cans to XCats, are leaking exhaust.
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Performed · outcome unconfirmed · Original poster
I Ordered new clamping sleeve and installed the FABSpeed CATs.
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Suggestion
The car should never experience any lag when adding sport cats, so you may just need to reset the battery after installation which helps resolve any problems.
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I am currently having trouble with the performance of my Porsche with
the newly installed 200c Cats. There is a considerable hesitation
accelerating quickly from a stop or at low rpm. This happens
consistently when aggressively pressing the acceleration peddle.
Installation went very well. New O2 sensors and air/mass sensors were
installed. All bolts were properly torque to manufacture
specifications. Battery was disconnected to reset the computer.
Sound is absolutely great! Acceleration is greatly improved.
To find if the Fabspeed 200c Cats were the cause or not, I decided to
remove the Fabspeed cats and have the OEM cats reinstalled. After
installing the OEM catalytic converter the lag during aggressive
accelerations from a stop or at low rpm was no longer occurring.
Currently the Porsche is accelerations as normal with the OEM cats.
The Fabspeed cats are currently off and I am running the OEM
cats. The Porsche is a 2002 996 with under 30,000 miles, fully
tuned. If anyone has any understanding of this problem let me know.
Have contacted FabSpeed but know information yet. The Cats installed
are not the same as seen in the last pic. Not sure if this change has
anything to do with exhaust flow.
I have the same cats and have noticed the hesitation at low RPM. My solution is simply to rev a little more when dis-engaging the clutch. You must be smoother than with the OEM cats. Maybe a flash of ECU would help. Im sure Fabspeed will chime in soon...
Ok, just got off the phone with FabSpeed...
They think there may have been an exhaust leak. I had all bolts torqued to spec but it was suggested to tighten a little more than spec and reset the CPU. I will let you know how it goes.
There is less back pressure. I've found that I just need to be more careful in 2nd gear when releasing the clutch so car doesn't bog down. Never a problem in first gear... Only short shifting to 2nd is where I found this issue.
You said new O2 sensors....when you went back to OEM, did you transfer these new sensors or use the old ones (presumably still left in the old cats)?
BTW...why did you get new O2 sensors? Were you having issues with the old ones?
There was no problem with the old O2, wanted all new o2 with new cats.
Just got done re-installing the FabSpeeds X Cats. The X Cats piping to Cans is slightly
smaller than OEM. Found a leak on both clamps. I will order new clamps to stop leak, hope this will solve problem.
I have had my Old-Style Sport Cats for about 3 years and i have noticed the same thing about Low RPM... never seem to bother me tho, but i know its not Normal. Fabspeed please enlighten us
Ok, I installed the new FabSpeed XCats. Hesitation the same. Checked for leaks and found both clamps, from the OEM Cans to XCats, are leaking exhaust. Tried to over toque but still leaked. The FabSpeed XCats pipe is slightly smaller than the OEM Cans.
OEM Cats to Can:
6.75” circumference.
2.15 diameter.
FAB X Cats To Can:
6.625 circumference.
2.11 diameter.
Not sure if new clamps will stop leak, with the discrepancy in diameters. Anyone know the if newer model XCats pipe cats to cans has the same diameter as OEM Cats?
I was really considering installing these at some point but I'm curious to know what Fabspeed thinks about this feedback. I'd love the sound and slight hp improvement but not if that means hesitation.
Guess I was wrong when I wrote Fabspeed will schime in....? An explanation from the manufacturer would be helpful to those customers new and old? Hello??? Fabspeed....anyone home?
I Ordered new clamping sleeve and installed the FABSpeed CATs. Will
install new clamp sleeve when they come in. Reset the computer and
torqued all bolts. Running great except for low end lag.
Hey Guys, sorry for the delayed response. This issue is very strange and we have not seen it before. I checked with many of my customers and they are not experiencing this problem at all. We have a bone stock 997 in the shop and we are going to see if the same problem occurs. The 996 and 997 use the same X Pipe Sport cat on both cars. If there's no leaks on the system or issues with the Cats, there shouldn't be anything wrong, especially if you aren't getting any kind of CE light. We use only the Highest quality HJS Sport Cats which are guaranteed not to cause any problems and the X pipe allows the exhaust gases to talk and improve flow balance.
This is a very unusual problem but we will try to track it down and find a solution for it right away. Thanks for being patient with us and I will be back with updates and answers when I have them.
Thanks,
I just installed a gently used x-pipe (cat delete) this weekend. Pretty simple install. I have only got to drive once but WOW! Even my wife noticed the difference in power around 3,500rpms! Feels like a good 20hp.
I got zero hesitation on any type of load. It does have a little hesitation revving the engine when its cold.
So far I am loving the sound and power! I have stock headers and a set of used cargraphics mufflers.
If we get slow at the shop I will put it on the dyno and see where it is. I don't have a base line...
Put new clamps on this weekend and still have the hesitation/lag
problem. There is a small leek with the clamp on the FABSpeed cat but
haven't driven much. We'll see if the leak seals up as I drive the
911 this week. Everything is running great otherwise.
weird.
I've got no low end lag on my C4S. Stock headers/mufflers with Fabspeed 200Cel cats.
Maybe there is a problem with your cats? Like a defect or something?
****ty, hope you get it sorted out!
My 200cell cats recently purchased do have a smaller diameter than the stock cats as well. I had to remake my muffler bypass pipes to fit and when running the mufflers I have to really crunch down the muffler-to-cat clamping sleeve on the cat side. Even when clamped super hard, it still leaks slightly on one side, enough to feel with my hand and enough to see with the water that spits out when the engine is cold. No hesitation or running issues at all: they work perfectly other than the leaking exhaust due to the smaller tube diameter compared to the stock tube size.
Wouldn't the different muffler size be explained by the different engine 3.4 and 3.6 ?
I remember buying some exhaust tips and because of a mistake I got a set of 3.4 one and they would not fit like the 3.6, they were too small as well.
That would explain it all.
+2
I'm actually thinking of purchasing the Fabspeed cats and Flash ECU. I current have there Exhaust, Headers, Tips, and Cold Air Intake but is not yet on the car.
Hey Guys, I hope everyone had a great new year. The car should never experience any lag when adding sport cats, so you may just need to reset the battery after installation which helps resolve any problems. After proper break in, the car should adapt and feel stronger throughout the RPM's. oojkoom and dotframe, PM Sent.
thanks,
Hi there
I did a cat less x-pipe on my 997.1 C2S, did battery reset, even tried a softtronic tune but nothing solved the low down hesitation and massive loss of low down power/torque. It's a bad modification, simply don't do it.
So were these problems ever resolved? I just got a warning light and confirmed one of my cats is on the way out. I'm not interested in dealing with hesitation problems.
PS-A wideband O2 sensor has a broader range of air fuel ratios over which it can measure accurately. This makes them more useful for tuning vehicles. A narrowband sensor (stock setup on production cars) is accurate right around the stoichometric AFR but drop off quickly when you get far away from it. So they're good for maintaining closed loop control, but not for tuning purposes.
I don't have a hesitation problem but I do need a bit more throttle to get the car moving from a standing start. This is something that threw me off when I first got the cats but now I don't even think about it.
Correct but in most cases, you can't just plug in a wideband o2 to replace a narrow band. You have to have the associated electronics along with it.
Also most o2 widebands have a limited running time(some measured in hours) compared to their narrow band counterparts. Only a few like NTK(found in the Honda VX, but costing $300) can go for a long time.
But as someone said, you shouldn't have to do anything to run 200 cell cats.
I'd be curious as to the folks reporting low end loss problems if they are running the 3.4L motors. I know companies like Cargraphic make two different cat bypass and high flow cat models for both the 3.4 and 3.6 motors. (thinking most likely a slight reduction in pipe diameter).
For those that are having this problem, can you please list:
Intake system on the car
What file is in the ECU (if it is not stock, please also list if it is custom or not)
Any other modifications done to the engine/intake/exhaust
Light Weight Flywheel or not
If it is an early 996 please state if it is E-Gas or not
stay away from Fabspeed products, they are crap in a Porsche, absolutely no reason to install them other than for sound but you probably will lose power, like you do when you install a sports exhaust on a car, I think you lose 20HP actually per the DYNO.
So you "probably" lose power, or you "actually" lose 20hp on the dyno? What do your dyno results show?
Please inform us as it sounds like you have definitive evidence that is contrary to what the manufacturer and other owners state.
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