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Should i repair this Catalytic Converter?

To fix the paid off car or to buy a new ?used? car, that is the question.

I have a 2003 Lancer OZ rally; it has 134,000 miles on it. Currently I drive only about 200mi a week but in May will be increasing that to 450mi a week.

Last November, I replaced an oxygen sensor and had the 100,000 mile check up (belts, pumps and such) totallying $1100. After two days, I was on my way to get the inspection, I am in Texas, and the service engine light came back on. Took it back to the shop and they scanned the codes to find the Front Catalytic Convertor needs to be replaced. Now, my original plan was to buy a new ?used? car in March of 2011 (all debt will be paid off,) hence the 100k check up, to make her last a little longer


1st question, how do I know the Catalytic Convertor in the back is still working properly?

2nd question and the true dilemma, do I go ahead and pay the $1100 to have a new C Convertor put in? Or get a car payment?

I appreciate any help you can give!

With thanks,


If everything else seems to be in working order, I’d replace the cat, IF it needs to be replaced. First, make sure that O2 sensor is working properly. It just seems somewhat suspicious that 2 days after you replace the sensor, the computer thinks that a cat failed… that is often detected by the O2 sensors…

(btw, does this actually have 2 cats? On a 4 cylinder?)

In any case, you should be able to get it for far less than $1100. The MSRP for a Mitsu part is $727.97 according to… who sells it for $582.38. lists a direct fit part for $385.89 (not legal in california). Labor for these things shouldn’t be over 2 hours ($150-180 or so).

Why was the oxygen sensor replaced?
Was the replacement sensor original type or aftermarket?
It’s possible the new sensor is causing the light.

Circuit makes a valid point…In any case, I would not replace the converter until a failed emissions test forced you to do it…

My first question is what age and mileage car are you going to be replacing it with, and what are the monthly payments?
Then remember at 450 miles per week the car value will depreciate rapidly, and any warranty with it will expire quickly.
My thought is 450 miles a week you might as well keep your current car and bank the money from a car payment for repairs and maintenance. (keeping in mind circuits post)

I called the dealership this morning to make sure it does have two cats, and they verified it. So since i was on the phone with them, i asked the cost of what they have on hand. He stated they had a “kit” now that works just like a new cat for around $380. and labor for it would be around $200(dealership.) Is this kit what you are talking about at

Yeah that is pretty much what is putting me in this position. It wont pass b/c the light keeps coming on for it:) Thank you for your reply!!

No sure if my first reply submission went through. the o2 sensor was replaced with an orginal type in November however, being a bad car owner, it probably went out in March. so that is what they are saying caused my cat to back up.

i was thinking of something not older than 2 years with less than 30k, however you bring up a good point. If i am going to drive the heck out of something, best it be a “beater.” And with the possibility of the cat only being a total of $610 & not $1100. i feel better about fixing her up again, taking better care of her here on out. Thank you very much for your reply!

That sounds about right -

As long as they give a warranty on the replacement (should be good for at least 1 year, preferably 2), I’d say go for it, unless you know there’s a serious repair coming.

Driving on a bad O2 sensor for that long could certainly take out the cat… still they should do a proper diagnosis to make sure the O2 sensor is behaving properly

10 4 Thank you very much for all your help!