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Car purchased with catless x-pipe. Tune, high flow cats or stock cats back on?

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YOUR RESEARCHCar purchased with catless x-pipe. Tune, high flow cats or stock cats back on?

Reported or suspected cause

variocam system kicking in

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1
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Suspected cause: 0
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Discussions that report identifying a cause: 1

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Reported cause
The power ramp after 4k is due to the variocam system kicking in.
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Car purchased with catless x-pipe. Tune, high flow cats or stock cats back on?

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Leading evidence: 'variocam system kicking in' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'variocam system kicking in' (1 discussions; 1 report identifying it and 0 suggest it). 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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Reported and suspected causes (1)

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variocam system kicking in

No successful repair reported for this finding.

1
Identified cause: 0
Suspected cause: 0
Reported fixes

Read evidence and context

Discussions that report identifying a cause: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Reported cause
The power ramp after 4k is due to the variocam system kicking in.
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Car purchased with catless x-pipe. Tune, high flow cats or stock cats back on?

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Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

2 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

Rennlist: 1 discussions

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POST 1 / ORIGINAL POSTEROriginal post

Hi everyone, first time poster long time lurker. I recently bought a 996.2 that came with some sort of catless x pipe. The far sounds incredible after 4k and almost feels like it has a turbo the way the power comes on. My concerns with the x-pipe is loss of the low end torque for around town drivability and bore scoring from a rich mix. The car doesn�t flick its check engine light on but definitely runs rich. It�s been on for about 10k miles so I�m hoping to take it off to prevent any future issues. Will a tune fix the low end torque and drivability issue / can the fuel ratio issue also be fixed? If so who could I reach out to tune my car? If I got the x-pipe will a tune be necessary?

POST 2Original post

How do u know its running rich? The cats have nothing to do with air/fuel ratio. Cats are an after treatment for the exhaust gasses. It may smell rich because its suppose to (with no cats). The precat o2 sensors(before cat) that tell the dme on how to fuel. First thing u need to do is scan the dme and get us the numbers. Lots if threads in how to read them but its all somewhat confusing. We need to see the short tearm fuel numbers. Cant help on a tune but a good tuner can pull the power up in the mid range. On my gt3 motor u had to get a tume to fix a mid range power loss due to an exhaust upgrade. The power ramp after 4k is due to the variocam system kicking in.

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