Skip the auto shop - Our mechanics make house calls

Q: How difficult would it be to replace the catalytic converter on my 1997 Chevy Blazer?

asked by on

How difficult would it be to replace the catalytic converter on my 1997 Chevy Blazer? There is a severe rattle coming from the catalytic converter from idle to about 2300rpm. Would it be possible for me to change it on my own?

My car has 162000 miles.
My car has an automatic transmission.

A: Hello. If the exhaust system is original, t...

Hello. If the exhaust system is original, that is if it is about 20 years old, you will probably end up replacing the entire system, consisting of the "Y" pipe coming off the manifolds, the converter, muffler, and tail pipe. The reason for this is that the catalytic converter mates to the "Y" pipe on one end and to the muffler on the other via flanges with three bolts per flange. These flanges both rust shut and are typically weakened once bent (installed) years ago and thinned out by rust.

You can sometimes attempt to salvage existing parts by using aftermarket flanges and/or split flanges but if the rest of the system is even as little as 5 years old it is not worth it. Also, in your configuration the converter is not set up with straight pipe on either end making retrofit to the existing system less convenient.

If you do replace the whole system, the most critical task is to remove the three nuts on each manifold flange stud without breaking or damaging the thread on the stud. If you haven't done this before, I recommend that you at least observe the procedure while someone trained completes the job, and then next time around you may have the confidence in taking on this type of job after seeing how it is done. It is a bit of work, and unless you have dealt with exhaust fasteners before, it can be tricky. If you would like a professional handle this, a certified professional from YourMechanic can come to your car's location to inspect the rattle and replace the catalytic converter for you if necessary.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Car loud with exhaust leak

If you removed the catalytic converter, then that may be the cause of your noise, since it works like a muffler to slow the exhaust down, and lower noise levels. The exhaust leak would need to be located to see...

Q: I changed th alternator I've changed all the fuses and whenever I turn on the lights the battery drains dead and the windshield wi

This may be a voltage regulator problem. As you may know the voltage regulator manages the amount of power the alternator supplies to the battery and other accessories. When this is not working correctly, the battery can be over charged...

Q: Truck not going into four-wheel drive

There are several things that can go wrong with the system on a Blazer. The switch is a part of the system and can possibly not be making good contact. There is a motor on the transfer case that engages...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.