Can a bad catalytic converter cause head gasket failure?
Running a vehicle with a bad catalytic converter over thousands of miles leaves drivers questioning whether the added engine stress triggers head gasket failure or if the issue is simply age-related. Drivers also encounter related hardware problems, such as finding iron particles accumulating in the intercooler.
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.
- 1Replacing the failed turbocharger unitDid this help you?
- 2Asking online forums for diagnostic opinions and mechanical adviceDid this help you?
- 3Replacing the MAF sensorDid this help you?
- 4Checking live data for wastegate commands and inspecting the actuatorDid this help you?
- 5Pulling the intercooler to check for metal shavings deeper in the engineDid this help you?
- 6Confronting the mechanic who installed the part to demand a resolutionDid this help you?
- 7Setting aside money in anticipation of a future catastrophic failureDid 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.
“I don't know much about cars can someone help me please? 🥺 There was a new fast clicking/chuffing noise while driving, then hard starting, severe juddering and stalling. There was smoke/burning smell around the turbo area, heat coming off it and the coolant expansion tank contents looked dark and vented vapour.”source ↗
“Mechanic put a new turbo without warning me that the hose was torn, because of it some debris got inside the turbo and now the fans look like this. The car is underpowered. Is my turbo gone or could something else cause the low power?”source ↗
“Yeah, I got that one haha. That will definitely not go back. I even have iron in the intercooler :)”source ↗
“I’ve been running my 2005 Subaru Outback for the last year (~25,000 miles) with a bad cat. A couple months ago (~5,000 miles) my head gasket started to fail.”source ↗
“Wonder if running the car with a bad cat stressed the engine and caused the head gasket to fail. Or if it is just age related.”source ↗
“Replacement MAF was manufactured by Delphi. But in my case, I still have the same problem before the MAF replacement.”source ↗
Where this came up
People with this problem also raised
- 4How to tell if a wheel bearing is bad
- 2Why is my new turbocharger screaming after a few hundred miles?
- 2Why do my car brakes need to be pumped?
- 11Why does my car stall when I step on the gas?
- 9What does a ticking engine noise and flashing check engine light mean?
- 8How to diagnose an engine code without guessing or replacing parts