p0420 w/ 2 year old magnaflow cat

The troubleshooting instructions for P0420 in the repair manual ought to do a pretty good job of distinguishing the possible causes.

Toyota Service Information and Where To Find It | PriusChat

 

Be interesting to see what diagnosis brings up for this issue I always thought if the O2 sensors were doing their job and in range the heaters working in the etc the only other prime suspect would be the converter maybe the Walker aftermarket unit can't take the self-testing that the car runs whenever it does run it and it's just ruined it? According to what I have read which is very little this seems quite suspect I don't know what Toyota does to the cat to make it be able to run this test whenever it wants to or what have you A lot of extra precious metal makes that happen okay sounds good so then other people that are going to manufacture a cat for this particular model need to up the game in that department I guess maybe that's what makes them cost $1,500 right?

 

I believe Walker is MagnaFlow but I'm not suggesting that you did anything cheap You bought the other one that's carb approved I understand perfectly well All I was saying is maybe Walker magnaflow didn't do some due diligence or something The test that the car runs whenever it does chap will be along to tell you all about it in a minute I guess and it runs some kind of flood test or something like same and maybe the magnaflow can't stand up to that for very long I don't have a clue it'll be interesting to see how this plays out thankfully I'm in it county with no admissions so I can just put a pipe there defeating the purpose I get that but at least I'm driving my car when needed.

 

So I guess this group doesn't have the Prius manual posted online Y'all use some subscription service or something along those lines? I guess I need to go buy me a paper copy that's how I've always done it with most of them I guess Gen 2 that's possible Gen 3 not so much.

 

I can send you a link to the Gen2 repair (both the 04-05 and 06-09 versions) manual on my web server, Just send me a PM and I'll reply with the link.

JeffD

 

@Tombukt2 Walker is Walker not Magnaflow.

As for the Magnaflow it should carry a 5 year warranty.

To the OP try using a can of Cataclean.

 

Yeah I guess pallone's still owns it etc etc I thought it'd been bought up by one of the majors it'll be next week or the week after as such. It'll just be interesting to find out what the end-all be all is to this.

 

Well there you go like I say I don't understand this I've bought converters from box lots for years they're usually marked under $3,000 over 5,000 blah blah blah whatever the deal is No specific model car specified on those types of catalytic converters at all they go on Corollas Nissan sentras trucks whatever It is only the Prius that gets this funny business whatever it is going on and that's that I bet the Corolla hybrid doesn't have this problem they say it has a much lower maintenance rate or issue then it's similar Prius counterpart both same engine and all that interesting.

 

The other user is correct, it should come with a 5 year or 50k miles warranty regardless if its carb or not. BTW, did you spend so much just for peace of mind since you didnt need to when when you're state suffices with any federal cat? I have a walker thats going on 3+ years and never no issues and comes with 5 year warranty. You should def check with the place you bought it from and you should have a claim if the p0420 is related to cat malfunction/failure...Either way, good luck.

 

Leaks are certainly the first of the listed trouble areas in the P0420 troubleshooting instructions in the repair manual, and the third step in troubleshooting (I'm looking in a Gen 3 manual, but I'm guessing Gen 2 would be similar). Usually those troubleshooting steps ought to do a pretty good job of distinguishing the possible causes.

Toyota Service Information and Where To Find It | PriusChat

 

Was the replacement a Denso or OEM from the dealer?

Have you tried doing a piston soak?

Various versions have been posted in the forum, the advanced search may find them. Maybe @alftoy or @jdenenberg will swing by soon.

 

I have both the early (2004-2005) and late (2006-2009) Gens Prius repair Manuals. Just PM me and I will send a link to the one you need on my Web server.

JeffD

 

Service Manuals - Google Drive