CEL - do I need new post cat 02?

[silverfoxS65]

Hey all
Car has stock tune and stock DP
(Was recently catless and STG2) but put cats back in and flashed to stock for inspection

Now I got this CEL

I guess need new downstream o2? Perhaps they got cooked in the catless DP for 8k miles

[Dwaynos]

This code usually means what it says, the catalytic converters are inefficient and could require replacement. This is a little unlikely though if they were fine before removal.

Very likely that you need a new post cat o2. Have the voltages and response of them checked either with a scope or via EOBD. Sometimes oem data pids will substitute a value to ensure correct running so avoid oem live data if possible.

[silverfoxS65]

Thanks mate
I ordered 2 new post cat sensors for $100 shipped from Rock Auto 👍👍
I'll know if this fixed it tomorrow 🤞