Catalyst below threshold. Likely cause said to be bad converter, according to the internet. Anybody got any experience to share? Car is 2007 Toyota Corolla LE with 150k miles.
Catalyst below threshold. Likely cause said to be bad converter, according to the internet. Anybody got any experience to share? Car is 2007 Toyota Corolla LE with 150k miles.
No other codes. Car burns no oil and runs very well. The entire exhaust system could be original. Do these catalysts fail this quickly? O2 sensor should set its own code.
You could try spacing the rear O2 sensor out to keep the code at bay. It worked a treat on my daughter's car.
Cousin_Eddie (Forum Supporter) said:You could try spacing the rear O2 sensor out to keep the code at bay. It worked a treat on my daughter's car.
Yeah, I saw a youtube vid where a guy did that. Prolly worth a shot.
Anyone ever used a product like Oxicat or similar cleaner?
1988RedT2 said:Anyone ever used a product like Oxicat or similar cleaner?
I have used water.
Find a place in the intake tract where you can introduce water with the engine running ar operating temperature. On a 1ZZ car with MAF sensor, that probably means leaving the duct assembled and attached to the throttle body, but tilting it up so that you can sneak a little vaccum line past the MAF. Find a way to get water into the vacuum line via a funnel or whatever. Hold the engine at 2000-3000 RPM and introduce water into the vacuum line so that it gets sucked into the intake manifold. As long as the engine is still running fairly smoothly, it should flash to steam in the combustion chambers and then scrub the cat substrate. A pint of water is probably plenty to do the job.
At your own risk, of course, but I've done it many times and never had any negative repercussions. And I have seen it reduce exhaust emissions by a large enough factor to help a failing car pass its biannual smog test. As long as the engine's happily consuming the water it should not be in any danger of hydro locking.
I live with a p0420 and p0430.... I ain't fixing it. Yet with a set of headers and y-pipe.
P0420 is almost always a wasted cat. Sorry to say.
O2 spacer might limp you through if it's just spent catalyst material, but 07 (I think) uses the downstream O2 for fuel trim fine tuning. Tricking it might make things worse if you take it out of the main flow. Water or Seafoam might give you a few more miles if it's carboned up. Nothing will help if a chunk of it has broken off and is sideways. If it's broken, it won't be long until bigger chunks start restricting flow.
Kid 1's 2010 Accord V6 has been throwing a 0420 code for more than a year. I sent up a code scanner just so she could clear the code when it comes up. I was just about to fix it properly when I learned that the car has three cats. $Yikes.
Someone here suggested Cataclean. I was skeptical, but I sent up a bottle and had her dump it into a full tank and then clear the code before a 300 mile road trip home. I filled the tank and dumped in another bottle before the return trip. Still no code and she was able to cruise through the state inspection.
I doubt that it's more than a short term solution, but the car has been code free for about two months now, so the stuff must be doing something.
I usually bang a downstream 02 sensor in them before cat replacement.
It's swapnostics, but if you do replace the cat, you still have a new 02 sensor...
Folgers said:I usually bang a downstream 02 sensor in them before cat replacement.
It's swapnostics, but if you do replace the cat, you still have a new 02 sensor...
If the code was a bad rear sensor, I can see doing that. But a catalyst code is because the front and rear sensor track each other too much- which is made worse when you put a new rear O2 sensor in.
Besides, rear sensors almost never wear out or break- they are in an ideal spot for long term survival in the exhaust.
If anything, the front sensor should be changed before the rear one with the hope that they will be different enough to not cause a cat efficiency code.
Woody (Forum Supportum) said:I doubt that it's [Cataclean] more than a short term solution, but the car has been code free for about two months now, so the stuff must be doing something.
I bet the back-to-back 300-mile road trips were a factor, too. A lot of cars see almost nothing but short trips and never get up to temperature.
Speaking of, I have to ask what kind of fuel the OP's been burning in the Corolla. I've heard of many dealership service customers with CELs due to dirty injectors, usually caused by buying fuel from the cheapest station in town because "it's all the same". The cars apparently disagreed. An occasional bottle of Techron or Berryman B12 or similar might not be a bad idea, and is so cheap it doesn't bear discussion.
alfadriver said:Folgers said:I usually bang a downstream 02 sensor in them before cat replacement.
It's swapnostics, but if you do replace the cat, you still have a new 02 sensor...
If the code was a bad rear sensor, I can see doing that. But a catalyst code is because the front and rear sensor track each other too much- which is made worse when you put a new rear O2 sensor in.
Besides, rear sensors almost never wear out or break- they are in an ideal spot for long term survival in the exhaust.
If anything, the front sensor should be changed before the rear one with the hope that they will be different enough to not cause a cat efficiency code.
Agreed. Cat efficiency is almost never because a rear O2 sensor is reporting incorrectly. It's not really a failure mode that O2 sensors get. I suppose it's possible, but in all of my years at the shop, I never had an 0420 that wasn't a bad cat. Changing the front sensor (also agree) might get you through an inspection, but my prediction is it will come back very soon.
Does the 07 Corolla use the same cat as an 03? If so, I have a good used aftermarket cat taking up space that could be had for the cost of shipping.
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