Catalytic Converter

B

Bballreich

New member
Hi all. I have a 2000 Limited that, according to my technician, has a CEL on due to code P0420. I think that indicates that the converter or some ancillary equipment may not be functioning properly. I haven't had this checked yet, but let's assume that the converter is bad. I live in California. I am of the opinion that, considering the original converter lasted 181,000 miles, and I enjoy driving the car and want to keep it in great shape, replacing the converter with an OEM unit makes the best sense. I know they are terribly expensive, but it's hard to argue with 15 years of reliable service. Thoughts?
 
Register to hide this ad
I am all for OEM everything, but a catalytic converter is not one of them. I know your options are more limited as being in California, but the OEM one is not worth the money.
 
You'll think that until you see the price. CA emission converters are STUPID expensive. I quickly looked up the part on Toyota of Dallas and you're looking at $1,242.00. Would be even more if you went to a local dealer.

I think I'd at least try putting in a new sensor to see if you can pass smog. Sensor is about $50 lol.

On my old Pickup I would just clear the codes, get the cat nice and hot and roll into the smog station. Passed every time that way and the CEL lights would turn on the next week...
 
csp said:
First of all it could be a number of things, not just a bad convertor. Engine codes are a starting place for diagnosis, not necessarily the actual problem.

You can google "Toyota P0420 code" to learn what is possibly going on.

One of the hits if you search: P0420 Toyota Catalyst System Efficiency Below Threshold Bank 1 OBDII Engine Light Trouble Code | Engine-Codes.com
Click to expand...

Tis very true.

Best way to know if it is your converter is you'll smell the sulfur and other gases in the exhaust. Will smell like rotten eggs or skunk spray.
 
There's several posts on here about that issue. Some people replaced their sensor and had luck, but my cats were actually bad. I went through the same dilemma...I plan on keeping mine for quite some time but Toyota thinks too much of their cats.
 
If it really needs them, Walker offers CA legal cats. You're looking at around $550 minus a $50 mail-in rebate for both direct fit assemblies or $300 (no rebate available) for two of their universal (but still CA legal) converters. The universal cats require cutting and welding,so you may be better off with the direct fit. Mine didn't require CA-spec converters but I did replace both cats with Walker direct fit assemblies last month.

But make sure it's the rear O2 sensor first before you start spending all that money on cats.
 
I corrected the P0420 code on mine by replacing the rear O2 sensor. I'm over 200k miles (on what I assume is the original converter) with a CA emissions vehicle. The sensor is about $50. It's worth replacing that first, because as others have said the converters are VERY expensive.
 
You can have both sensors checked, AND you can test the temp increases of the converter at inlet and outlet. You should not be guessing about this stuff, it's way too expensive. I just went through this on my wife's Altima. All kinds of fantasies about running lacquer thinner in your fuel, standing on your head and timing the monitors before having it tested. The internet is the conspirators wet dream.

In my case the Converter was bad, fortunately Nissan cuts you a slackburger on the price because they know they installed poor quality convertors to start with. So a few hours and $387 later I only had to drive about 15 miles to get the monitors to ready status and it passed with no problems. Added benefit was it actually runs better now.

For the record the sulfur smell is NOT necessarily an indicator of a bad convertor. A rich mixture will do that too.

Absolutely correct about the quality of OEM, but at that price you may consider a lesser quality if people are getting 75% life for 40% cost.

Have it checked, don't guess!

:phone:
 
IBallEngineer said:
You can have both sensors checked, AND you can test the temp increases of the converter at inlet and outlet. You should not be guessing about this stuff, it's way too expensive. I just went through this on my wife's Altima. All kinds of fantasies about running lacquer thinner in your fuel, standing on your head and timing the monitors before having it tested. The internet is the conspirators wet dream.

In my case the Converter was bad, fortunately Nissan cuts you a slackburger on the price because they know they installed poor quality convertors to start with. So a few hours and $387 later I only had to drive about 15 miles to get the monitors to ready status and it passed with no problems. Added benefit was it actually runs better now.

For the record the sulfur smell is NOT necessarily an indicator of a bad convertor. A rich mixture will do that too.

Absolutely correct about the quality of OEM, but at that price you may consider a lesser quality if people are getting 75% life for 40% cost.

Have it checked, don't guess!

:phone:
Click to expand...

It will cost more than $50 to have the diagnostics done, and the O2 sensor probably needs to be replaced anyway with that many miles on it. The easiest thing to do is replace the O2 sensor and reset the codes and see what happens. While there are other things that could cause this code, a failed O2 sensor is BY FAR the most likely, with the converter being the next most likely. Spending money on diagnostics isn't always the smart thing to do when you have a common failure like the O2 sensor.
 
Last edited:
jeremyc74 said:
It will cost more than $50 to have the diagnostics done, and the O2 sensor probably needs to be replaced anyway with that many miles on it. The easiest thing to do is replace the O2 sensor and reset the codes and see what happens. While there are other things that could cause this code, a failed O2 sensor is BY FAR the most likely, with the converter being the next most likely. Spending money on diagnostics isn't always the smart thing to do when you have a common failure like the O2 sensor.
Click to expand...

I agree, most shops will charge an hour of labor at around $100 for diagnostics. Most shops will just tell you to replace the O2 sensors with any exhaust issues since it's the easiest fix (shops love to throw parts at problems) and then you're out $150. Or you just beat them to the punch and replace the sensor at $50.
 
gamefreakgc said:
I agree, most shops will charge an hour of labor at around $100 for diagnostics. Most shops will just tell you to replace the O2 sensors with any exhaust issues since it's the easiest fix (shops love to throw parts at problems) and then you're out $150. Or you just beat them to the punch and replace the sensor at $50.
Click to expand...

Plus, if you end up replacing the cats, you want new sensors anyway. Any shop that does it will insist on it. Better to do it yourself and keep them from charging you triple the cost. Just make sure they know sensors are new. So if they have 75k+ or you don't know, do the rear one, see if the code goes away. Then do the front if it doesn't. They were end-of-life anyway.

I killed a P0420 50k miles ago just by changing the rear sensor that had 90k on it. No diagnostics done except to rule out exhaust leaks. I normally agree with [MENTION=102597]IBallEngineer[/MENTION] but not this time. There is no easy test for a degraded sensor. Any fail that is easy to test for will throw another code. You need a live scanner to evaluate these sensors.

But before you do ANY of that--check for any exhaust leak forward of the rear sensor. Our gaskets are dying if original--so are the bolts.
 
Last edited:
I dont know if anyone mentioned this but clogged cats are usually caused by bad o2 sensors. Making the car run rich and causing sulfer build up. So if you keep the sensors working and not let the CEL go forever you usually dont clog up the cat. But again all toyotas seem to make that sulfur smell.
 
TheDurk said:
Plus, if you end up replacing the cats, you want new sensors anyway. Any shop that does it will insist on it. .
Click to expand...

I recently found out why they insist on it. When I replaced the turbos on my car I put on new downpipes, but reused the O2 sensors (they're $150 each in this case). They both failed within weeks of getting the car back on the road. That required pulling the downpipes back off to put new ones on, which is about a five hour job without a lift. PITA!

Apparently this is common, and the general consensus is the ceramic parts inside the sensor get really brittle with old age, and the stress of removing them and re-installing is too much for them.

The sensors on our trucks are the flange type, whereas my car has the screw in type, so they may not be as sensitive to it, but with high mileage it's good insurance to just swap them out.
 
jeremyc74 said:
I recently found out why they insist on it. When I replaced the turbos on my car I put on new downpipes, but reused the O2 sensors (they're $150 each in this case). They both failed within weeks of getting the car back on the road. That required pulling the downpipes back off to put new ones on, which is about a five hour job without a lift. PITA!

Apparently this is common, and the general consensus is the ceramic parts inside the sensor get really brittle with old age, and the stress of removing them and re-installing is too much for them.

The sensors on our trucks are the flange type, whereas my car has the screw in type, so they may not be as sensitive to it, but with high mileage it's good insurance to just swap them out.
Click to expand...

In your beast you should be emulating the o2 sensor from the wbo2, take that stock shit out! LOL, just joking.
 
TheDurk said:
Plus, if you end up replacing the cats, you want new sensors anyway. Any shop that does it will insist on it. Better to do it yourself and keep them from charging you triple the cost. Just make sure they know sensors are new. So if they have 75k+ or you don't know, do the rear one, see if the code goes away. Then do the front if it doesn't. They were end-of-life anyway.

I killed a P0420 50k miles ago just by changing the rear sensor that had 90k on it. No diagnostics done except to rule out exhaust leaks. I normally agree with [MENTION=102597]IBallEngineer[/MENTION] but not this time. There is no easy test for a degraded sensor. Any fail that is easy to test for will throw another code. You need a live scanner to evaluate these sensors.

But before you do ANY of that--check for any exhaust leak forward of the rear sensor. Our gaskets are dying if original--so are the bolts.
Click to expand...

Well I will admit a certain amount of ignorance here, in respect to the 3.4 in the 3rd gen. But I will agree to DISAGREE. I didn't find it that hard to research how to check the 02 sensors or the Converter on my wife's car. Now if you told me 98% of the time it's one sensor, and could prove that, I'd go with your idea of dropping a Fitty on it. Call me weird, but I prefer to KNOW what I'm changing is actually bad.

On another note, I agree that a good tech is going to insist on new sensors(I didn't replace hers so I must not be a good tech), even if they are working. And I'd go even further to say that some techs might say they'll only do the job if you replace them, even if you just replaced them. I'm sure the dealer would.

The other thing is even though I'm a Do It Yourself kind of guy, I like to support the techs because they are the ones that make it possible for us to learn all this stuff. The information filters down from them. And when I ran the auto electric shop I had to deal with DIY'ers who changed the battery/starter/alternator before bringing it to me and then got mad when I told them what it cost to repair professionally. I know, it's a personal thing.

:violin:
 
I haven't researched the T4R yet, but every O2 problem I've had only required the procedure and an ohmmeter to diagnose.
 
csp said:
I haven't researched the T4R yet, but every O2 problem I've had only required the procedure and an ohmmeter to diagnose.
Click to expand...

The only thing you can diagnose with an ohmmeter is a blown heater, and that is NOT the only thing that can go wrong with an O2 sensor, and it will NOT throw a P0420. This is true on any car.
 
You must log in or register to reply here.

Members online

Total: 299 (members: 1, guests: 298)

Forum statistics

Threads
278,306
Messages
3,554,046
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top