Catalytic converter clogged without check engine light
A catalytic converter can fail and severely restrict exhaust flow without triggering a malfunction indicator lamp, leading to gradual power loss and an inability to climb hills. Because diagnostic trouble codes do not always appear, drivers struggle to confirm whether the restriction is actually inside the exhaust system.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1taking out the upstream O2 sensor to let it breathe
- 2getting the dealer to diagnose and replace the catalytic converter
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“If the cat is clogged you will almost certainly have an MIL. If you don't have one now how do you know it's the CAT?”source ↗
Reasonable_Tax_5351 · r/AskMechanics · 1 upvotes