Catless tune with cats

truebluedevil02 · Dec 16, 2012

Talking with a buddy about my car and came up with this question.

Can you run a catless tune on these cars while still having the stock cats installed? Doesnt a catless tune simply turn off your rear O2 sensors? Just curious. If anyone knows for sure, please chime in. Thanks.

CobraHuck · Dec 16, 2012

Curious too, mainly for when I will need to put the stock midpipe back on for emissions

ViciousJay · Dec 16, 2012

Yes a lot of tuners ditch the gas dump in their tunes

Shaun@AED · Dec 16, 2012

Yes.
And Yes, the cats are still working and doing their job. You can 'set up' the tune to not throw a code with an off-road pipe by telling the ECU to ignore that the rear O2 sensors are reading the same as the front (Off road pipe instance). This will cause the Rear O2 monitor to be 'incomplete' however (in a 2011+). Via SCT we do not yet have access to the parameters that allow us to change what the ECU is looking for in the Rear O2 signal. (There is a way to complete the check monitor with an off-road or high flow cats, but not yet available via SCT.)

H-TownMachI · Dec 16, 2012

Shaun@AED said:
(There is a way to complete the check monitor with an off-road or high flow cats, but not yet available via SCT.)

Any ETA when this might be available through SCT. I have high flow cats and it would be nice not to have to switch between tunes when emissions check comes around.

Squamishcoyote · Dec 16, 2012

Can you turn off cat protection without a tune though?

GrabberBlue5.0 · May 5, 2020

Shaun@AED said:
Yes.
And Yes, the cats are still working and doing their job. You can 'set up' the tune to not throw a code with an off-road pipe by telling the ECU to ignore that the rear O2 sensors are reading the same as the front (Off road pipe instance). This will cause the Rear O2 monitor to be 'incomplete' however (in a 2011+). Via SCT we do not yet have access to the parameters that allow us to change what the ECU is looking for in the Rear O2 signal. (There is a way to complete the check monitor with an off-road or high flow cats, but not yet available via SCT.)

Hardcore necro posting here... I'm running Stainless Works LT's without cats and have the car dyno tuned. if I throw stainless works cats on the car (tired of it being too loud) does the same apply as with stock exhaust? Probably a redundant question when reading the reply from Shaun@AED, but I feel compelled to ask anyways

boostedgt12 · May 6, 2020

also interested if needing retune if being tuned for catless and switching to catted

9TMAREEE · Jul 7, 2020

For what its worth I just removed my O/R x and reinstalled my stock H pipe with cats because ive gotten tired of the smell and after messaging Lund they advised that it was totally fine to still run the catless tune on the car. Anyone else know whether COT is disabled in the catless tunes or if there are any other shortcomings by running a catless tune on a catted car?

Catless tune with cats

truebluedevil02

Captain Jackstands

CobraHuck

Member

ViciousJay

Well-Known Member

Shaun@AED

Well-Known Member

H-TownMachI

It's the Hamburglar

Squamishcoyote

Wheel Hoppin

GrabberBlue5.0

Member

boostedgt12

New Member

9TMAREEE

Member

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