Catalytic converter code(P0420)?Solution inside

HHHMMMM, I will have to try this..curious as to why it works...

 

Since the code is thrown when the second O{2} sensor shows no change with the first, the pipe may simply delay the gas exchange and mix it long and slow enough to 'spoof' the control computer that the catalytic converter is running. There is a phase change and reduction in amplitude so mixing fresh with stale gas would look to the sensor as if the catalytic converter had reduced the noxious gasses.

IF I were doing the same thing, I would use a microprocessor to spoof the second O{2} sensor and 'have a happy.' In fact, I might as well spoof both sensors to run an extra lean mixture . . . even at high power settings. This of course would be totally illegal not to mention hazardous. Today we barely hear about carbon monoxide poisoning so we've become lax about the safety precautions.

Bob Wilson

 

My 2001 (250K plus miles on the ODO) got a check engine light with P0420 code under conditions of unseasonally high mid-day ambient temperature combined with a highway lane closure on a steep up-grade which caused all cars to be driven slowly and most probably with inadequate engine cooling.

I reset the check engine light and erased the P0420 code using a medium quality OBD-II CAM tool, and then repeated the very same drive later in the week under conditions of no traffic and normal seasonal low night-time temperature, which included rain, and the check engine light with P0420 code DID NOT REOCCUR.

It was unusual for me to use my 2001 on that drive, anyway, as I usually take my 2012, and the east-bound climb up to the nearly 2,000 foot mountain pass is an easy drive on the car, whereas the reverse climb is a very difficult drive for the car (either one), but the 2012 can more than handle this drive, whereas the 2001 has a pretty tough time.

As long as I keep the 2001 in my coastal county, and don't attempt the drive over into the inland county, with its difficult return grade, the 2001 seems up to the job, as was proved just the other day during an in-county trip which involved only modest grades and low, coastal temperatures.

 

I just did this last night on my 2005 Prius. It was extremely tight getting it all to fit in there, but I got it. Hopefully it keeps my CEL off.

 

Excuse me for saying so, but I hate this "solution." This "solution" turns a clean running car into a gross polluter. Why bother having a Prius if you're going to defeat the emissions controls? That brown haze? It's ground ozone, very bad for you, your family, your pets.

I replace my bad cat with a new aftermarket one that cost about $200 including new O2 sensors. My friends at Midas welded it in to the existing pipe for about $100. Even folks in California and NY can order them and have them shipped to a UPS or Fedex store out of state, take a little vacay and have a muffler shop do the install.

 

That little CEL on the dash never bothers me much. Why not just leave it alone?

 

Because it masks other codes? Those of us who must do emissions testing every other year can't pass inspection if there's a code.

 

This works for sure

 

Tight fit on my 2007 as well. Got by the O2 sensor monitoring test without out the 0420 so I zoomed right over to the smog check place. Win.

 

Can this then be used to pass the CA smog test?

 

Yes. Take a weekday trip to Phoenix or Reno and have the converter replaced. If you can set it up in advance, you can have the converter shipped to the shop where the work will be done. I don't know for sure how CARB smogs your car, but here in Tucson it's just a matter of hooking up to the obd2 port and taking a reading (check for codes.) I had mine done last week, it passed with flying colors!

If you do it, I'd have Midas do the work, mine here in Tucson does fantastic pipe welding!

 

Installed the spark plug non-foulers onto my 2007 Prius downstream O2 sensor (212,500 miles) yesterday. Cleared P0420 code with my Techstream software, had helper drive car around while I observed live data while sitting in the passenger seat, worked great and after driving the car a couple hundred miles, all is good.

 

This works on gen 3!

 

As far as I understand getting the Cat Replaced out of state still voids your Smog in California. California does a visual inspection of the Cat
To make sure it has the OEM stamp on it, they also check to make sure the O2 is not extended. Of course, there are always techs that see a good OBD scan and don't go just do a quick visual check to ensure you have a Cat.

 

Only worked for 10 months. P0420 just came back today.

That must mean the catalytic efficiency has gotten even worse, to the point where even with the spacers the sensor still detects too much fluctuation. So I guess I'd need a better spacer, with a smaller hole or longer distance to buffer the gas exchange even more. There are also spacers with integrated mini-cats, but who knows if they work better or not.

 

Because you're cheap and/or poor, you drive a prius to save fuel costs and don't care enough about the environment to invest in expensive repairs.

Catalytic converters get destroyed by upstream issues; typically if your cat fails then you also have to repair or replace the engine, or the replacement will eventually get destroyed again. When you could just hack it for a few bucks and forget about it, or worry about it later.

I kind-of agree though, our car's exhaust smells really bad with a dead cat. I think smog should always be tested with a tailpipe sniffer, because on-board diagnostics can always be cheated. Then nobody would have any choice but to get it repaired properly.

But because it's such an easy way out...

 

Regarding the cat, I had an non-california honda 1997 crv that failed smog test. It was all good expect for the idle HC reading.was a bit too high.
After trying a number of things, it still failed, and then I discovered it had a hollowed out cat. So what surprised me greatly is that it ALMOST passed the CA smog without a cat, it only effected idle emissions. Now maybe its different for other cars, but given a prius doesn't actually idle the engine much at all, not having a working cat is probably not much of an impact on air quality.

 

I don't think any such claims can be made without doing the testing. Anything else is just wishful thinking.