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.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1taking out the upstream O2 sensor to let it breatheDid this help you?
- 2getting the dealer to diagnose and replace the catalytic converterDid this help you?
- 3cleaning the catalytic converterDid this help you?
- 4welding in a new piece of exhaust tubing or a resonator in place of the converterDid this help you?
- 5using a spoof circuit to bypass the downstream O2 sensor codeDid this help you?
- 6Using a catalyst cleanerDid this help you?
- 7Monitoring sensor data with an OBD2 scannerDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, 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 ↗
“I have a 2005 Honda Accord LX 2.4L, and the catalytic converter is clogged i’ve removed and cleaned before, but I’m pretty sure it clogged up again and I’m guessing it gets clogged because my car burns quite a bit of oil and causing exhaust restriction.”source ↗
Where this came up
People with this problem also raised
- 10How to tell if a catalytic converter or oxygen sensor is bad
- 3How much does a catalytic converter replacement cost?
- 2How do I know if my catalytic converter actually needs replacing?
- 3Can I drive my car with a stolen catalytic converter?
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