Punching Out My Cat

[MY1PATH]

Ok with a title like that I'm sure sombody on here is gonna be mad at me lol but heres all the Catalytic Converter innards in my shop trash...

 

 

Recently I failed smog and the results point to a bad Cat, This weekend I am going on a road trip and I wanted to get rid of that annoying exhaust ratting on the frame that I have been ignoring since the engine change (engine and exhaust sit a little lower that it did with the 3.0) when I pulled the exhaust out to modify it to fit better I looked into the cat and saw the core turned sideways. Well it failed me smog already so its worthless and this clog will cuase me issues on my road trip (has been causing higher than normal temps already and now I know why) so I did the quick-n-dirty and punched it all out with a prybar so I can make my drive safely.

So what caused this you might ask? The root of the cause is that in the ~6 years that I have been running this cat my truck has flooded many times. I had bad luck with failing TBI injectors and then an intermittent short that kept the injectors open longer from time to time... But if the final straw was when I switched to MPFI and my Defective ECU kept the # 1 injector open at all times. (also led to the death of that 3.0)
Simply put, Flooding and running really rich is really bad for cats. It eats up the catlyst, and deteriorates the cores untill the break up and or get loose. Then sometimes they block the passage causing exesive heat and back pressure. So If you have flooding, or you have been running rich for a while; INSPECT YOUR CAT.

[adamzan]

This happened on my old truck, while I didn't see it myself, it is what the shop told me...And a new cat allowed me to pass my e-test and go on my cross america road trip . I had been having problems with misfiring and running rich...I was just a dumb kid back then who was too dumb to know cars needed tune ups lol

[nunya]

Shoulda replaced it with a test pipe. Even bad cats as long as it ain't empty have scrap value and our wd21 cats are usually on the better end of the scale. That's my disappointment with the situation

[vagabond]

I punched mine out last summer, I knew I was going to have to install a new one before it needed to be smogged again

[MY1PATH]

Shoulda replaced it with a test pipe. Even bad cats as long as it ain't empty have scrap value and our wd21 cats are usually on the better end of the scale. That's my disappointment with the situation

So I missed out on a few dollars, Acquiring a test pipe by tomorrow would have cost me more than I could get for the cat (last I priced a PF cat it was $35 in scrap value)

A few smacks later and I have a small resonator, instead of a cat

 

I'm surprised B is not yelling at me yet lol

[nunya]

Dam, scrap price sucks there! thats a 3 digit cat here as a partial with the guy that buys the ones we save from cars we junk here.

 

 

Just wait, he's old and slow. He'll be here to yell about not feeding your cat

[Precise1]

I'm surprised B is not yelling at me yet lol

No point.

You explained the situation, it is temporary so you can take your trip without issue, then you will repair it so you can pass smog. Makes perfect sense to me...

I can supply you with a stock cat or the info on a CARB legal Magnaflow if you wish.

Now, if you were one of those pecker heads who punches out the cat because of WooHoo 3hp gain and F-everyone else, you can't tell me what I can do 'cause I'm a 'Murican, then yes, I'd call you on it.

 

Have a safe trip and Happy Holidays. If you find yourself this way, you are welcome.

 

B

[MY1PATH]

Dam, scrap price sucks there! thats a 3 digit cat here as a partial with the guy that buys the ones we save from cars we junk here.

 

 

Just wait, he's old and slow. He'll be here to yell about not feeding your cat

 

That was last I checked in WA, I have no Idea what it is here in SoCal. 3 digits? For the huge OEM or for aftermarket? Magnaflow direct fit for the PF come in at around $130-150 all the time on ebay but they have a smaller core section.

 

No point.

You explained the situation, it is temporary so you can take your trip without issue, then you will repair it so you can pass smog. Makes perfect sense to me...

I can supply you with a stock cat or the info on a CARB legal Magnaflow if you wish.

Now, if you were one of those pecker heads who punches out the cat because of WooHoo 3hp gain and F-everyone else, you can't tell me what I can do 'cause I'm a 'Murican, then yes, I'd call you on it.

 

Have a safe trip and Happy Holidays. If you find yourself this way, you are welcome.

 

B

 

In my case It was more than 3 HP It was a difference I could feel but then again it was corked lol

[nunya]

Guess that would make sence to specify the "good" one to have is the factory one. Aftermarkets always bring less for some reason (generally the smaller core most have as you said with the magnaflow).

 

Yea, amazing the difference being able to ACTUALLY exhale makes!

[MY1PATH]

The factory one is probably overkill and over priced. I'll get a new magnaflow and see if they will smog me again.
They wanted me to go to the "Smog Referee" because its an engine CHANGE not an engine REPLACEMENT.
Both TBI and MPFI are listed as fuel injected vehicles but the engine appearance not matching the vacuum diagram under the hood set them off a little and when I failed the tail pipe emissions they said no way, see the Referee...

[92Path_68CJ]

Shoulda replaced it with a test pipe. Even bad cats as long as it ain't empty have scrap value and our wd21 cats are usually on the better end of the scale. That's my disappointment with the situation

 

About three years ago my cat got cut out. When the PD told me how much it was probably worth I about keeled over.

 

 

[msavides]

I at first thought this was an animal abuse thread,

 

 

I had the same issue with my cat. I punched it out. I then bought a new one. I welded ball fittings to both the punched out cat and the new one. I will swap my new one in every 2 years for the emissions test, then swap the punched out one back in.

 

I passed the first time and failed 2 years later. All the numbers from the test remained unchanged (put only 1000 miles on my pathfinder in those previous 2 years). California reduced the max emissions by 20%. I guess to try and get the older cars off the road.

 

F you California.

Edited December 6, 2013 by msavides

[adamzan]

Here the emissions used to be an idle test and a 40kmh on a dyno...Now they've gone to a scan test for obd2 and for the older ones they do a 2 speed idle test, at idle and 2500 rpms...My old truck always came close to failing but this new to me 94 passes with flying colors.

[Alkorahil]

They must be hard core in Cali checking the emissions labels.

[MY1PATH]

They must be hard core in Cali checking the emissions labels.

 

They are against most modifications, even though my modification is better for the environment than TBI (assuming everything else works lol). So when my vacuum diagram obviously didn't look like the vacuum system they were inspecting (they check the function of EGR and the carbon canister purge) they noticed right away.

[Precise1]

They must be hard core in Cali checking the emissions labels.

Yes.

 

B

[Nefarious]

I got a magnaflow hi-flow 2.5" weld in cat for 75$ on ebay and that was shipped to canada. I've had no issues at all with it, would definitely recommend.

[ejin4499]

The factory one is probably overkill and over priced. I'll get a new magnaflow and see if they will smog me again.

They wanted me to go to the "Smog Referee" because its an engine CHANGE not an engine REPLACEMENT.

Both TBI and MPFI are listed as fuel injected vehicles but the engine appearance not matching the vacuum diagram under the hood set them off a little and when I failed the tail pipe emissions they said no way, see the Referee...

 

why not swap your hood with a MPFI pathie so the vacuum diagram matches what you have? How would they know at that point?

[ahardb0dy]

I did the same on the cat on my 90 sentra but mine looked clogged on the inlet side, I know that points to another problem but I gutted mine and the car runs better and MPG went up 4 MPG, the only thing I didn't like is it became noisy, not the exhaust being louder but the sound of the exhaust flowing through that empty cavity ! It was driving me crazy so I eventually straight piped it and just removed the empty cat all together. Now it's quiet again ( plus the stock muffler I replaced with another stock one), only thing I notice with out the cat is a drone at highway speeds.

[Kafike]

i pulled my cat out his past summer for being clogged. Hell, I didn't know they were worth anything. I just tossed mine. Why are they worth so much?

[SilverPath]

Because they contain a good amount of precious metals, I don't know what the WD's have, but in general they have Platinum, or Rhodium and Palladium. Pd is acts as the oxidation catalyst and Rh is a reduction catalyst while Pt does both.

There are also other metals in it but in a lot less quantities like Cerium, Manganese, iron and nickel

[Alkorahil]

i pulled my cat out his past summer for being clogged. Hell, I didn't know they were worth anything. I just tossed mine. Why are they worth so much?

 

 

They use small amounts of platinum and a few other precious metals inside them to react cemically with the exhaust to make it more friendly. Platinum is uber $$$$ per ounce.

[Kafike]

Dang, wish I knew that back in June. I wouldn't have tossed it. Oh well, live and learn.

[Alkorahil]

http://en.wikipedia.org/wiki/Catalytic_converter

 

The catalytic converter's construction is as follows:

1. The catalyst support or substrate. For automotive catalytic converters, the core is usually a ceramic monolith with a honeycomb structure. Metallic foil monoliths made of Kanthal (FeCrAl)^{[citation needed]} are used in applications where particularly high heat resistance is required.^{[citation needed]} Either material is designed to provide a large surface area. The cordierite ceramic substrate used in most catalytic converters was invented by Rodney Bagley, Irwin Lachman and Ronald Lewis at Corning Glass, for which they were inducted into the National Inventors Hall of Fame in 2002.^[2]
2. The washcoat. A washcoat is a carrier for the catalytic materials and is used to disperse the materials over a large surface area. Aluminum oxide, titanium dioxide, silicon dioxide, or a mixture of silica and alumina can be used. The catalytic materials are suspended in the washcoat prior to applying to the core. Washcoat materials are selected to form a rough, irregular surface, which greatly increases the surface area compared to the smooth surface of the bare substrate. This in turn maximizes the catalytically active surface available to react with the engine exhaust. The coat must retain its surface area and prevent sintering of the catalytic metal particles even at high temperatures (1000 °C).^[15]
3. The catalyst itself, most often a mix of precious metals. Platinum is the most active catalyst and is widely used, but is not suitable for all applications because of unwanted additional reactions and high cost. Palladium and rhodium are two other precious metals used. Rhodium is used as a reduction catalyst, palladium is used as an oxidation catalyst, and platinum is used both for reduction and oxidation. Cerium, iron, manganese and nickel are also used, although each has limitations. Nickel is not legal for use in the European Union because of its reaction with carbon monoxide into toxic nickel tetracarbonyl.^{[citation needed]}Copper can be used everywhere except North America,^{[clarification needed]} where its use is illegal because of the formation of toxic dioxin^{[citation needed]}.

[djratlif]

I had to do this with my 2000 Frontier, I then had a low catalyst efficiency code spring up. Solved that by buying a set of spark plug anti foulers from napa for $6. These anti fouler plugs then are drilled to receive the downstream sensor, effectively removing it from the exhaust stream enough to trick the sensor into thinking the catalytic converter is working fine. Sorry for the brief explanation here as I'm currently surfing the net at work lol but it is explained online in several other spots if you search for it. This won't help if you live in a state where the "sniffers" are used in the tailpipe for the emissions inspection either. Helped out immensely here in NY though.