2000 Camry 4 cylinder Primary Converter bad-engine light on

Hi all

Got an expensive puzzler here. got a 2000 4cyl camry my mechanic says has a bad primary converter that exists up by the exhaust manifold. the second converter, downline was replaced already-no change in problem. he says they are really expensive (near $1k from Toyota with small warrantee.) and the aftermarket ones he puts in for similar Honda problems burn out in 6 months and fail inspection again. this is a Calif spec Camry in Mass with 111k miles. Any one have experience with this problem? It won’t pass the MASS emissions come Feb.

If the primary convertor was the problem, why would you waste money by replacing the second convertor? The computer only inspects the functionality of the first convertor when you are driving.

What I would recommend is that you search salvage yards, and get a replacement from them. You can do this very easily online.


mistaken for sure and a waste of money-can’t cheap out repairs I found out.
My mechanic -real smart guy-said he swears it is the gasahol they sell with 10% ethanol that kills them eventually. real ticked off as the car is only worth a couple g’s and a converter fix is crazy money in a 10 year car. think I will check the used route out if there.

Two things will kill a convertor:

Too much gasoline in the fuel mixture.
Think lots of cold starts with short trips.

Too little fuel in the fuel mixture.
Think air leak causing the engine to run really lean, or overly lean computer programming in order to meet emissions regulations.

This will cause the convertor to break apart into chunks, and depending on how close it is to the engine, parts can get sucked back into the combustion chamber and damage the cylinder walls, leading to massive oil consumption and driveability problems.

Nissan Altimas of similar vintage as your Camry with the 2.5 liter 4 cylinder engine had the latter problem. Typically the car starts showing signs of issues around 80k to 120k miles. Car is out of warranty, and the owner now needs to buy a new engine, convertor, and 02 sensors.

Good luck.


It is my understanding that Federal law prohibits a salvage yard from selling a used catalytic converter.
Here is an article which should help you to understand your problem a little better: http://repairpal.com/OBD-Code-P0420-Toyota The article states that all catalytic converters, sold in CALIFORNIA, must be ORIGINAL EQUIPTMENT ones, or, certified, specifically, for California (law passed Jan. 2009).
When catalytic converters are simply replaced when a codes come up, the underlying cause will STILL be there, and the code (and, perhaps, damaged catalytic converter) will re-occur. The engine can purr like a kitten, and still, have defects in the emissions which harm the oxygen sensors and catalytic converters.
If your mechanic can’t perform the diagnosis for the problems (“Let’s change some parts,” is NOT a diagnosis), you need another mechanic who can.

I think the Mass. test has been gutted and now only involves making sure the CEL is working properly and is not lit when you drive in for the “test”…

After you reset your CEL, (disconnect the battery for 30 seconds) how long will the light stay off?? Maybe long enough to get through the “test”…They may plug in to the OBD-II connector but if you clear it just before the test, you MIGHT squeak through. Some cars will show a “not ready” message (can’t test) and some won’t…It’s worth a try before you scrap the car or spend big bucks…

That’s the problem: after market converters out there state they are 49 state legal-not Calif spec. so you end up going to Toyota. the primary converter on the 4 cylinder models are up top next to the exhaust manifold. the computer has been reset and it comes back on in 5 miles. guess it is cooked like my wallet will be come inspection time. the code that comes up is the one for emissions/converter failure. that will get you a reject in this lovely state. Not happy with Toyota but seems Honda has same issues. maybe it is the crap gas we have to use now.

If the primary convertor was the problem, why would you waste money by replacing the second convertor?

Logical, but I think you have been misled by the terminology. I’m probably somewhat familiar with the geometry of this vehicle as I spent a couple of days slithering around under a 1999 Camry four cylinder this Summer replacing the catalytic converter. There is only one Catalytic converter in a normal 1999-2000 Camry and it sounds like it is the one that the OP calls the ‘second converter’. It appears that California vehicles must have an additional converter (the OP’s “primary converter”) inserted between the normal converter and the engine. There’s probably (barely) enough room to do that. [Indeed, I found a picture of the thing here http://www.partsgeek.com/gbproducts/BN/7956-02002756.html?utm_source=google&utm_medium=ff&utm_term=00+2000+Toyota+Camry+Exhaust+Manifold+Toyota+Exhaust+Manifold+4-cylinder+with+Catalytic+Converter%2C+OB2+California+Compliant+-+Meets+CA+Emission+Stand+Replacement+Exhaust+Manifold&utm_content=BYY&utm_campaign=PartsGeek+Google+Base Note that it’s only $338 before mark ups, but installation won’t be cheap as it looks to also be the exhaust manifold ].

The downstream O2 sensor in a non-California car is a couple of feet behind the “second converter” in a separate pipe segment with a resonator in it. My guess would be that it is the same in a California car.

One would think that as long as the “second converter” is working and there aren’t any holes in the system, the tailpipe emissions would be at least as good as any other 49 state car. But the vehicle computer probably has it’s own ideas about what it expects to see.

And who knows how many O2 sensors this thing has or what the computer expects them to report.

I don’t see much choice but to either pay for the California converter, or configure the car as a non-California car. That probably means installing a non-California exhaust manifold and very likely replacing the computer with a non-California computer. That may be morally OK, but it’s maybe not that cheap, is probably illegal, and may not work.

My mechanic says when he resets the computer it then it must be driven for about 40 miles to properly get all the 'flag’s in the computer reset/ I made about 5 miles before the damn light came back on. Reset the battery doesn’t clear the codes as they are stored in a folder on the engine management computer-they have to be cleared off by a tech(some cars can’t). Surprised other Camry 4 cyl owners out there haven’t had check lights/emissions problems at normal miles. Or am I just unlucky?