Catalytic Converters (Both) Are Bad...

you can try to use cataclean. i noticed a bit of improvement, not much though. worth it? yeah, id say so.

i still ultimately bought 2 new cats from rockauto for around 700 and installed them myself.

 

I just dropped off my truck at the exhaust shop. Three months ago, I installed some TRD headers and a Magnaflow Catback exhaust. Two weeks ago, I got a P0420 code. I didn't have $2k for new cats but I could afford $1k for both cats from Magnaflow along with the o2 sensors. I just dropped it off and the guy told me he didn't think it would correct the problem!? He said Toyota's are sensitive when it comes to their cats. My question is if that's true then how can Magnaflow sell cats if it's not going to clear my CEL?. If this doesn't clear it, I'll be one unhappy camper. You'd think if you bought brand new headers,both o2 sensors brand new and two brand new cats from one of the most reputable names in exhaust systems and a brand new cat back exhaust you'd be good to go!... to be continued

 

It could very well be that but being that my cats are rusted out and 14 years old I figured they could use replacing. I'll make sure to go back and re tighten everything but if that is the case,they lasted two months without throwing a code. Also the CEL is off again off again which makes me think it possibly may be cats are getting to their limit?

 

Hey guys, my 04 Tacoma turned on its CEL and turns out I need the front CAT. Does anyone know if this can be bolted on? I don't have a welder and they are charging me $1300 for the part and install!!! That's from a muffler shop! I looked at the part itself and I found it from around $150-200.

Thanks for any info

 

Did you have to weld? I need to replace mine but don't have a welder and don't have $1500 I was quoted for it.

 

Here's my story....last Oct.I purchased a 04 dc,trd bone stock.didn't even get it home....420...I inspected the cat myself....magnaflow.took it back to them,they ordered off brand cats,900 bucks..on them...same result...back again..this time they took it to dealership,they said 02s were good but cat wasn't strong enough.so they played the massive price for stock units,i held them in my hand before they went on.toyota motor Corp.stamped with a yota symbol...the real deal......2 new 02s......and the same thing.2 drive cycles...420.....now I'm sure there is guys out there thinking this is another issue that is causing this....well I wish someone could tell me what it is.truck runs like a dream and gets great gas mileage.idle is dead steady,plugs are clean and not burnt or saturated.just did valve covers and bought plugs,but didn't need them.what I can tell you is you can't stand at the rear of the truck while it's running....it will make your eyes water...strong exhaust smell.like there isn't a cat there at all.the only item I haven't removed and inspected my self is the maf sensor.it is in spec as far as resistance reading go.....I checked....useing alldata pro when I did my own diag.on this since they could get it right.....any ideas????

 

Crawl under your truck and look. If the cat is welded in place you will have to cut and replace. My magic 8 ball is having a hard time looking under your truck from here.

Most exhaust parts can be assembled using clamps and u bolts.

 

Your engine is running rich. New cats won't solve that. Its odd that you're only seeing a rear code and not a front though. The front sensor monitors a/f ratio so the engine can adjust, the rear just checks the cat is working.

If it wasn't for the smell id say bad rear o2 sensor. Any cat should be "strong enough" for the engine its installed on from the factory. It's not like toyota just heard about these things and grabbed the first one they saw to try out.

 

This happened to me about 3 years ago. My truck has 310,000 miles and still running strong. Bought the simulator from urdusa.com and haven't had any issues. We have pretty strict emissions testing and never have a problem. Only takes a few minutes to put on.

 

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Just added a kn filter to the stock airbox.maybe a little more air will help.on the rich thing,does toyota not have a dtc for rich at idle or rich under heavy load..?if the upper o2 sees rich condition after asking for a leaner mixture(less injection time)it should set this code....

 

Stock air filter setup flows more air than the engine can use, k&n won't help. A bad injector could be the problem. The ecu should adjust to the point it can't adjust anymore and then throw a code, and it should reach that point before a cat can get overloaded. But things don't always work the way they're supposed to. I had a jeep years ago doing the same, no codes but exhaust that smelled like rotten eggs.

Your front o2 may be having issues, reporting a lean condition when one doesnt exist and the engine is going rich to compensate.

 

Well the engine is a air pump......paper or more like cotton filters these days are fine but do restrict air flow...fact.....the more you free up the flow of air the more efficient the pump is...fact....as far as injectors go..they are just off and on solenoid controlled by the drivers in the ecm.inputs from such sensors as the b#s1,maf or map sensor and crank and cam sensors.tells the ecm when to fire injectors and coils.that's all in closed loop though...all have a preset for cold startup.the ecm doesn't look at o2 till the temp sensor has reached a voltage threshold..today's engines are a little more complex but it's still a air pump with a box attached so the government can control emissions...I have come to the conclusion this is not that important.I will always pass inspection...and the truck is a joy to drive

 

If your engine can move 2.7 of air, and your airbox/filter combo can supply 5l of air, and you increase that flow ability of 100l of air, your engine can still move 2.7l of air. Fact.

Removing all restriction, on most modern engines, provide at best a boost that's pretty much imperceptible unless you have equipment to measure it. Fact.

Most people see bolt ons that advertise as "Up to 15hp gains!" tend to forget that 0 is included in that up to amount. Fact.

Putting in a system that allows the engine to 'breath easier' isn't going to correct an engine that has issues elsewhere. Fact.

A leaking injector, a plugged injector isn't On, or Off as intended. Fact.


That's annoying isn't it. And comes off as pretty pretentious. Fact

 

Well after a long drive,158 miles,the kn slide in filter does free up some lower rpm horse power.long hill climbs that my truck would usually unlock torque converter to hold speed on.it did not today.had tank full,usually take this drive with half tank.I was sure it would stuggle up those long hills with the added weight of a full tank and cab(took all my girls to the uwharrie mountains to see nanny)but only would loose a couple mph.the main thing I noticed was one road you pull out and drive up a long hill usually the truck holds third gear till the top.today I let out the throttle and was in top gear at the top and converter locked up rite after the top.at a pit stop the girls went in the store I stayed out and left the truck running(my girls hate a hot truck)I walked to the back of the truck and stood...no where near as bad as it was.it was never rotten egg smell of a faulty cat.my truck just had a excessively rich smell,like a Quadra jet that needed some love.not so much today.only time will tell but the thick cotten filter I removed, seem to choke my engine at lower rpms.with the mileage definitely up,fully loaded cab and tank still held speed up long hills,not to mention a.c. was on all day.I think I may have beat the rich condition with a quality air filter...it was like driving a new truck.I did resurface my rear drums and popped in some leveling blocks and performed a alignment.even Janelle said the truck just feels different.