Ok, so I have a 2003 Toyota Corolla LE (manual). The check engine light came on so I took it in for a diagnostic to our trusted mechanic. After his tests, he concluded that the converter needs to be replaced (and the computer reprogrammed). However, I spoke to the dealership and they said the problem can often be misdiagnosed, so I took it in to the dealership for a 2nd opinion. He also diagnosed a problem with the converter.
Here’s my dilemma: My trusted mechanic said that it NEEDED to be replaced, or I risk doing more damage to the car.
However, the dealership mechanic said the converter was running at “low efficiency,” but it is not completely broken - and the car would continue to run fine (with no risk of more damage) as long as I can live with the check engine light on (which I can).
The estimate for the repairs was $2000 (eek!!!) BUT I’ll fix it if it NEEDS to be fixed.
The car has been running a little slower than usual, but its also about to hit 90,000 miles… I know nothing about cars or converters and I’m two very different responses to the same problem… just want to do the right thing!
What should I do?
Thanks for your help!
If your state requires emissions testing, your car’s registration can’t be renewed if the car fails that test–and if the CEL is illuminated, the car will not pass the emissions test. Thus, you may have no choice about whether or not to replace the converter.
However, I would be concerned about two underlying issues–
What caused the converter to go bad? (The cause should be addressed if you plan to keep the car.)
Why is the car sluggish? (This should also be addressed if you plan to keep the car.)
How many miles on the car? That system is warranted longer than the rest of the car. Check with the dealer about the warranty. I don’t recall the time or miles, but hopefully you are covered.
It’s also possible the problem could simply be aged transmission fluid since fluid can affect torque converter operation. Since you have 90k miles on the car this means it should have been changed 60k miles back.
If the fluid has been changed then ignore this comment.
If it turns out that a converter is really needed then price this around at a regular transmission shop. Odds are the job could be done for far less than 2 grand.
I interpreted the problem to be with the catalytic converter, and ok4450 has interpreted the problem to be with the torque converter. OP–please clarify for us which “converter” you are talking about, because otherwise you are going to become very confused by conflicting types of advice.
It has to be catalytic, the engine light is for emissions only, torque converter really has nothing to do with emissions, not in a way that would trip a light anyway.
Emissions parts are covered by 105K/8 year? 7? warranty. It’s required, above/beyond any other warranty. This should be covered. The part, at least (which is the expensive part). And no, it will never really harm your car, unless it clogs.
The car is a manual, I doubt it has a torque converter.
It’s a stick shift OK, no torque converter. This is a CAT issue…
Driving the car with a degraded converter will NOT cause any damage, it just raises emissions levels a little bit…Rarely, converters can fuse and get plugged up. This would produce the “sluggish” feeling you mentioned because of increased exhaust back pressure. They can test for this…If the back pressure is high, then yes, replace the converter before further damage is done
One more thing. The devices that made the CEL come on are called oxygen sensors. You probably have two, front and rear, before and after. I would replace those FIRST (much cheaper) before I replaced the converter. Your mechanics probably tested them, but still…Do the cheap things first…And you can get an aftermarket converter MUCH cheaper than $2000. Shop around for that…
You’re correct. My brain was out to lunch and did not return. Why I was thinking torque converter I have no idea. 
From the Auto Zone parts lookup, your Corola seems to have “regular” short band oxygen sensors, and a “regular” catalytic converter.
Often, things that are wrong with the engine can, adversely, affect the catalytic converter and the oxygen sensors. The engine needs to be checked, and repaired, before anything expensive is done.
Here is a checklist the mechanic(s) should be following: http://www.obd-codes.com/p0420
I thot he was talkin’ about the catalytic converter!!
First thing to check is if your car’s emissions controls are still under warranty, I think it’s 8 years or 80k miles, whichever comes first, so how many miles?
I believe that you are correct about the length of the emissions warranty. Since the OP did tell us that the car has almost 90k on the odometer, there is a chance that Toyota might cover it as a “good will gesture”, but the warranty has run its course, so the OP has to be prepared to shoulder the cost by himself/herself.
The catalytic converter is covered for 8 years/80,000 miles. But you should ask that Toyota make a good will adjustment on the price of replacing the converter. Explain to them that you purchased a Toyota vehicle because of its reputation quality and reliablity. And because of this you didn’t think you would have to replace a catalytic converter on a Toyota just 10,000 miles out of the warranty.
Can’t hurt to ask!
Tester