2003 Toyota Corolla Oxygen sensors and Catalytic Conv

I purchased a certified used 2003 Corolla. I’ve had it going on 3 years. I had an extended warranty on it and of course after it expires my Oxygen Sensors and catalytic converter need to be replaced.

The dealership is asking $1999 for the repairs. With the economic times that we are in currently, that’s not a price I can afford.

Is it possible to get it done at a cheaper price and if so approx how much of a difference from the dealership?

How long can I drive my car with these parts that need to be replaced?

Here in Maryland, Advanced Auto Parts quoted me on prices on those parts. Do they have good parts?

Why do you believe they need to be replaced? How in depth has the analysis been?

A fault code indicating a bad converter could well be just a bad O2 sensor.

If it ultimately turns out that you do need a new converter, a “direct fit” OEM replacement from Advanced, VIP, or any other parts place will do just fine and save you money. NOT: an “OEM replacement” is not the same as an “OEM part”, it’ll be manufactured as a direct replacement but by a manufacturer that does not sell directly this part to Toyota, but it’s usually just as good.

That’s a good question. I went to put gas in my car 2 weeks ago and then like a couple of days letter the check engine light came on. I went to AAMCO to do the free check engine light service and that’s what they told me. Then I went to a mechanic (who went M.I.A) that a friend referred me to and he said it was the same thing.

How about the 8yr 80,000 Fed Warranty on your cat. do you qualify? The combo part failure diagnosis also makes me ask if you are confident in the diagnosis. Lots of room to get it wrong in this area.

There are actual tests for 02 sensors and cats. some places replace parts based simply on the presence of a code. The 02 sensor rules the roost in the cat. 02 sensor hook-up. I am purposely keeping things simple here.

Bosch brand parts are fine. Advance has Bosch. http://www.autozone.com/autozone/catalog/parts/partsShelf.jsp?categoryDisplayName=Routine+Maintenance&fromType=parts&fromString=search&parentId=cat10003&currentPage=1&filterByKeyWord=oxygen+sensors&navValue=14200117&categoryNValue=14299999&fromWhere=&itemId=prod10688&displayName=Oxygen+Sensor&searchText=oxygen+sensors
Getting a code is NOT a reason to change a part. It is reason for an able, qualified, mechanic to perform checks and tests. Finding such a mechanic, from reports from other posters, seems to be a difficult task. Keep asking around.
Something is wrong with the engine (tune, leaks, etc.) CAUSES the code to be set. The CAUSES have to be taken care of, first. From those results, step two is decided upon.

I agree with the crowd here. Codes for oxygen sensors and catalytic converter usually indicate old oxygen sensors that are getting slow to respond. Converter may not be bad at all.

I have driven my last three cars over a quarter-million miles each, one Toyota, one Volvo, and one BMW, and I have never replaced a catalytic converter.

Unless the flaw is covered under warranty the only reason to bring it to the dealer for service is for the nice coffee they have in the nice clean waiting room.

Dealers are no better (or worse) than independent mechanics for almost anything you might need done on your car.  They will almost always charge more per hour and often more for parts and supplies.  They also tend to look at repairs a little different than the independent. 

A dealer may well recommend work that strictly may not be needed, but could be connected to the problem or maybe replace a part when a little repair would fix it ALMOST as good a new.  

There is no need to bring your car to the dealer for any service other than service that is going to be paid for by a recall or original warrantee.  During the warranty period be sure to have all required (as listed in the owner's manual) maintenance done and to document all maintenance work.

I suggest that most people would be better off finding a good independent (Not working for a chain) mechanic. 

Note: Never ever use a quick oil change place. They are fast cheap and very very bad.

Thank you! All this information is GREAT!!! I am learning a lot about this. It would be helpful if I can have tips for finding a good independent mechanic? If there’s certain questions that need to be asked.

Is there anything or type of feeling a person would feel if those parts were to go up? For example hesitation in the car or something? My car drives as if nothing’s wrong with it.

About the best way to find a good mechanic is to use the word-o-mouth meter. Ask around. You need a mechanic who is NOT known as a big parts changer. Try to find one who seems to understands diagnosing problems, rather than using expensive parts in an experimental way.

I’ll bet they say a P0420 code. My daughters 03 Corolla just had this. I cleaned the connector for the front O2 sensor and it cleared it up. Cost, about a dimes worth of alcohol and a Q-tip.