Sold: WTB: Catless downpipe with cel delete

[MK5B58]

I’m looking for a Catless downpipe with cel proof for my 3.0 B58 Supra. Any of the 4 below will work:
Armytrix
FI
Kenji
MXP

Sponsored

 

[IsThatASupra?!]

Catless downpipe with cel proof

Is your ecu unlocked?

 

[MK5B58]

Is your ecu unlocked?

No, unfortunately. Hence I’m looking for a catless downpipe with cel proof for now.

 

[IsThatASupra?!]

No, unfortunately. Hence I’m looking for a catless downpipe with cel proof for now.

A catless downpipe physically removes the catalytic converter(s), which means the stock O2 sensors will see values outside the expected range. The stock ECU is programmed to expect certain readings from those sensors — especially downstream of the cats. If it doesn’t see what it expects, it will trigger a Check Engine Light (CEL).

Even brands that claim “CEL-proof” or “OE style” don’t actually change the sensor signals — they just try to approximate OEM geometry or use spacers. On a locked ECU, the only way to avoid a CEL reliably is software calibration (tuning) that either:

• Disables the downstream O2 sensor checks, or
• Recalibrates expected ranges so the readings look normal to the ECU

(Hence not possible without unlocking)

Without an unlocked ECU or a proper tune, the stock ECU will always throw a CEL with a catless downpipe no matter what brand you choose — Armytrix, FI, Kenji, or MXP.

 

[MK5B58]

A catless downpipe physically removes the catalytic converter(s), which means the stock O2 sensors will see values outside the expected range. The stock ECU is programmed to expect certain readings from those sensors — especially downstream of the cats. If it doesn’t see what it expects, it will trigger a Check Engine Light (CEL).

Even brands that claim “CEL-proof” or “OE style” don’t actually change the sensor signals — they just try to approximate OEM geometry or use spacers. On a locked ECU, the only way to avoid a CEL reliably is software calibration (tuning) that either:

• Disables the downstream O2 sensor checks, or
• Recalibrates expected ranges so the readings look normal to the ECU

Without an unlocked ECU or a proper tune, the stock ECU will always throw a CEL with a catless downpipe no matter what brand you choose — Armytrix, FI, Kenji, or MXP.

lol

 

[IsThatASupra?!]

Looks like I learned something new. I typed up what I knew and had AI clean it up since I browse the forums now and then and was just trying to help. My bad - I didn’t know there were catless downpipes that don’t throw CELs.

 

[IsThatASupra?!]

https://www.supramkv.com/threads/fs-fi-exhaust-cel-proof-race-downpipe-a90-supra-nib.35371/

 

[MK5B58]

https://www.supramkv.com/threads/fs-fi-exhaust-cel-proof-race-downpipe-a90-supra-nib.35371/

Thank you, I purchased an armytrix catless downpipe

Sponsored