Code P0420 and weird symptoms.

alright guys

Driving along this evening and my truck threw out this code

P0240 for Catalyst system efficiency below threshold

Truck model - 2011 Toyota Tacoma 4cyl 4x4 auto
Exhaust- Aero Turbine

Here are my symptoms-

Rattling noise on cold starts until it gets to running temp as well as warm starts (when engine temp is below 140*)

pin hole in a weld the muffler shop had welded a year ago...

I have an ultraguage and the code cleared no problem and I drove another 35 miles home... Highway speeds as well as city speeds.

As I neared home in a 35-40 MPH zone (speed limit was fluctuating due to construction zones starting and stopping) the exhaust got LOUD! I mean like it went from a purring kitten to a roaring lion!

I have mulled over ideas and I am going to take it to a local muffler shop that I know is reputable but id like some input from maybe someone who has had a similar or the same issue.

 

My guess would be an exhaust leak and that may have caused an O2 sensor failure or just thrown the P0420 code, due to the potential leak.

Without seeing your truck in person, it's hard to fully diagnose the problem.

RG

 

http://m.carcomplaints.com/news/2015/toyota-tacoma-rattling-noise-enhanced-warranty.shtml

The google machine has solved my issue... Now the question is will Toyota try and say that because I have an aftermarket exhaust that they won't cover it.

 

you have a 2TR-FE?

Disregard, you have one.

 

Yes sir I do! lol.

 

I hate to break it to you, but you need a catalytic converter.

 

Thank you.

I did figure it out.

Appreciate your help!

 

No problem!

 

Yep, new cat needed. Just a week ago I had this same code and symptoms on an old Nissan Maxima that was my daily driver before buying my Taco. Not sure what it will cost to fix a Taco but my Maxima repair was just a little over $300. The good news is now no more rattling and the P0420 is gone. Glad to get this fixed because the Maxima has become the car for my teenage drivers who I will not let touch my Taco.

 

P0420 does not always mean a cat. JS

The rattling to go along with it, i don't know.

 

Correct, P0420 could also be a bad O2 sensor, but the rattling is likely the internals of the cat falling apart. The combination of rattle and P0420 is a tell tale sign of a cat gone bad.

 

Working for Toyota in service the p0420 code is 99% the cat

 

I've never had a cat go bad in all my vehicles, so I can't comment on that. But it makes sense.

Replaced plenty of O2 sensors tho.

 

Have you tried to clear it and see if it comes back? Then it would more than likely be the o2 sensor

 

Hmm, that made me laugh.

 

@The Hunter How are swim lessons?

 

Local dealer said the same thing a few weeks ago, wanted big $$$ to fix. Replaced the left side post cat sensor for $80ish and problem solved.

I'm not saying your wrong, but a P0420 is a sensor code.

 

It's a 2015 and that's not covered under warranty?

 

2005 4Runner, plus did my 2002 4Runner a few years ago

No issues with my 2015's, except for my first one being totaled by an idiot.

 

Took it to Toyota. They will be replacing it for me under the recall F0U couldn't be more pleased with this dealership. Every dealer in VA I talked to told me to fuck off.