Skip the auto shop - Our mechanics make house calls

Q: Check Engine light; catalytic converters failing

asked by on

The Check Engine Light came on. Two codes came up saying two of the four catalytic converters are failing. This caused my truck to fail a smog test. I noticed my coolant overflow kept draining down to nothing after I filled it, but I don't see a leak.

Hi there. It sounds like you have a few issues going on here. If the catalytic converters are failing, then the converters will need to be replaced. They tend to either fail and become clogged causing a loss of engine power, or they simply fail and no longer react as they should. As for the loss of coolant, this engine has a history of head gasket failures even if the engine has never gotten hot. Most of the time this occurs on the driver side of the engine. A block test will reveal the problem area, but many times I’ve had to use a bore scope to look inside of the cylinders to find where the coolant is going. It is typically the rear cylinder on the driver side. If you need further assistance, a certified mechanic, like one from YourMechanic, will be able to diagnose the coolant issue.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: 2 major issues

The code P0453 is for the purge control valve; it's most likely bad and needs to be replaced. The ticking noise is possibly the oil pressure dropping too low at idle and the camshaft followers are getting noisy. Have the...

Q: Ac has no vacuum

The o-ring size is very critical. Often, o-rings have to be procured from the dealer to ensure the right part. Components in the system can only be tightened using the OEM torque values. Under tightening and over tightening will create...

Q: When putting my truck into reverse and let off the brake its starts squealing until I put it into drive. I think its the U joints

Hi there. What you are describing could be caused by multiple components being worn out or faulty, ranging from a U-joint to input shaft or even non-related to the driveline - such as a worn out serpentine belt or pulley....

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...