P0420 code but no cat

Texas does not have passenger vehicle inspections anymore and no smog on 25 year old or older vehicles.

 

I did some more research and realized that it's actually illegal in my state not to have a CARB compliant cat so I went with the Walker CalCat CARB 81978. Seems like the CARB ones at the very least have a longer shelf life than the EPA federal standard ones.

I'll keep you guys posted on how this thing holds up.

 

I've never installed a cat outside of a dealership setting so it's been a while since i've seen this but some cats have a "break in" of a specific idling routine. Chev's (where I worked) haven't required that since the early 2000's but I don't know where aftermarket technology is at.

Read the instructions for your cat to see if you have to "break it in"

 

The cat is the reason there is the egr.....

it seems when you're purring down the highway the cat backfeeds infrared radiation back into the heads....
because its so close to exhaust manifold....
left unchecked........it will blow a gasket

egr reuses spent gases back thru the cylinders to help cool the cat and its radiation down

5vz's are not prone to this.......but the others sure are


some later 2rz dropped the egr.........but have 2 cats to break the radiation

 

Umm .. nope

Catalytic converters combine HC and CO into CO2. It is mounted close to engine on purpose so it will get hot quickly on startup and start working sooner rather than later

The EGR routes exhaust gases back through the engine to help lower combustion temps and prevent the formation of NOx. Manufacturers got away from EGRs when variable valve timing showed up because they were able to achieve the same goal by slightly overlapping the opening and closing of the valves

Not sure where you heard about infrared radiation

 

When the element is working correctly at hwy speed....its glowing bright red

the internal steel pipe acts just like a waveguide.... red long waves...

when you shrink down systems so much....you get sub-system interference
'its a little car thing'


watered down combustion at hwy speeds is undetectable
unless towing or climbing.......which u should be using a 5vz for

 

They only glow bright red when there is a crap-ton of unburned fuel going down the exhaust. Converters don't like raw fuel. That's why they make the CEL blink when there is a misfire situation happening. They're trying to get you to stop driving before the cat gets ruined. And if it gets ruined before 8 years/80k miles the manufacturer is on the hook for a warranty replacement.. so they make it blink to try and get the driver's attention

 

when the 4 bangers get up in age

the egr tends to stick.....

if it sticks shut......and drive at prolonged hwy
then your risking a head gasket



right there on either cyl 2, or 3, or both

 

On here we've seen a ton of these




If you do drive a 3rz /2rz just be careful/aware......obviously on the exhaust side

 

Wrong again. You can completely disable the EGR valve and it will have no effect on the mechanical operation of the engine. It will just pollute a bit more than designed. People used to disable them all the time in the 80s and 90s

 

This no1 reason a Tacoma has been sitting around for last 10yrs

waiting on someone to fix it........or buy it


Again egr's main function is to cool down the head

and it really mostly only stays kick-in at hwy speeds


my brothers 2017 prius still has egr on it


WHAT YOUR SAYING IS ALL 5VZ AND 4.8 TUNDRAS ....which have no egr...
are operating in violation of federal emissions laws.....
.....so somehow toyota 'got to them' to look the other way

If this is uncovered......are they all gonna have to surrender their trucks to be crushed by the feds.....for spreading NO'x poison


or are there like little men that live inside the engine and process all this....secretly

or all just the 4 cylinders an inferior product

 

Corvette guys like the GESI cores over the magna-flow cores.
This isn’t a race truck, “down low torque gains” are negligible. I would weld one in, we only get one earth

 

No, it is for tailpipe emissions. The cooling system keeps the head cool.

You need to take an automotive training class

 

Ended up going with the Walker CalCat CARB 81978 because it was a direct fit bolt on type....come to find out I'm definitely going to have to at the very least re weld the hangers / part of the exhaust to make room for the spare tire.

On an unrelated note does anyone have a recommendation for a beginner welder? After some research im thinking of getting some kind of flux core because it seems more practical for someone that's just doing it in my backyard.

 

Because that engine (for whatever reason toyota decided) doesn't have vvt

 

ny here as well. I bought both CARB compliant cats from rockauto 4 years ago both around 300, with a one piece exhaust that was 120, no problems since, replaced header with oem toyota

 

Good to know....I'm still debating whether or not I want to buy the one piece exhaust or try to Frankenstein the current exhaust I have since its still in really good shape.

Really want an excuse to buy a welder is what I'm getting at here..

 

The one piece is nice ,then it's only 2 sets of 2 bolts needed,aside from the upper cat to header

 

I bought the harbor freight flux welder( 20__30 amp) to do some frame work, it's all still holding together

 

Thanks for the suggestion

And how do you feel about the weld quality? I've heard mixed reviews about the flux core welders. People seem to say that they can be kinda slaggy but other than that they make pretty solid welds