Cut out the cats and replace with a straight pipe

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Bella1992

Bella1992

10 Year 15 Year
Joined
Mar 22, 2009
Threads
65
Messages
633
Location
Gilbert AZ
So I see the 420 code did electronic fix to trick my oxygen sensor.

I have been code free for a couple months now.

I think I'll just cut out the cats & Weld on a straight pipe, how difficult is this? I don't know if I get the welder up in between the top of the pipe and the floor of the truck.
 
Bella1992 said:
So I see the 420 code did electronic fix to trick my oxygen sensor.

I have been code free for a couple months now.

I think I'll just cut out the cats & Weld on a straight pipe, how difficult is this? I don't know if I get the welder up in between the top of the pipe and the floor of the truck.
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I learned years ago that it is much easier to let the pros at a good muffler shop do the welding for me. They get to do it all day long. Been real happy with Apache Muffler on Main and Extension in Mesa.

How ya gonna deal with emmisions w/o cats? John
 
Keep me posted on how it turns out. Contemplating this as well.
 
Have you considered welding in flanges so you can remove your straight tube an put the cats back in? You might need the cats when you see the smog test station someday.
 
i give up... google has failed me. What is the 420 trick? i would like to lose the cats... if i can do it without check engine lights
 
You could remove cats and bust out the catalyst with a pipe or other preferred method. Then reinstall empty cat housing. No one is the wiser. Of course I would NEVER do that. (Big brother is always watching)


...via IH8MUD app
 
ADEQ defiantly does a visual check. You can gut the cat, but they will look for it to be there.

Not sure on these engines if you'd gain much if anything by taking it out of the mix...
 
FYI, if you remove your cats you can sell them to a recycler. We replaced the two original ones on our 92 with a single cat and sold them for 50 bucks/piece. The muffler shop might also tell you that they have to keep them. $, Duh?
 
Most muffler shops wont help you remove your cats unless you know the guys personally. They can get a huge fine if they got caught. I would make a straight pipe, you can buy the flanges online. That way you dont have to worry about welding in tight spots.
 
How much power do you think you'll get from this mod? Enough to warrant the money spent and possible inspection issues?
 
half k cruiser said:
Just to be clear, you are going to run a muffler after this straight pipe ? Also, why are you wanting to get rid of the catalytic converters ?
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I only want to get rid of catalytic converters because I have a suspicion that they might be bad. I earlier had the 420 code. I fixed it using YouTube. The spark plug Geefeller trick did not work, so I chose the $3.20 electronic fix by purchasing some pieces from RadioShack. Now I have no check engine light. However I have heard that when catalytic converter start to go bad the internals begin to break up and restrict flow. So I only want the float to be good. I wonder if it will ruin my engine if I do put in a straight pipe.
 
Bella1992 said:
I only want to get rid of catalytic converters because I have a suspicion that they might be bad. I earlier had the 420 code. I fixed it using YouTube. The spark plug Geefeller trick did not work, so I chose the $3.20 electronic fix by purchasing some pieces from RadioShack. Now I have no check engine light. However I have heard that when catalytic converter start to go bad the internals begin to break up and restrict flow. So I only want the float to be good. I wonder if it will ruin my engine if I do put in a straight pipe.
Click to expand...

A straight pipe will not ruin your engine. It will also not help it. The best setup is going to be with a fresh converter and the proper o2 sensors. Because you are not running an actual o2 your engine is not able to see and compensate for what is going on in the exhaust. My advice would be put it back to stock.
 
As I understand it the first O2 is critical to fuel mixture but the second O2's function is to confirm that the cats are working correctly and to help calibrate the first O2. you can get away with simulating the rear O2

on my Supercharged Tacoma I had the cats go bad. It caused a lot of back pressure as the grids deteriorated and clogged themselves. It also made the second O2 send bad signals which through off the calibration of the whole feedback loop and caused it to surge from mega rich to super lean under load.
I hollowed out the first cat and got a very large generic second cat. I left the second O2 functioning normally. It ran awesome, but that's also compared to clogged cats and messed up monitoring previously although I think it ran better even compared to how it was before the cats went bad.
With just the one big cat it still passed smog but just barely.

Also: If you are working around the pieces and junk that comes out of a bad cat wear good protection as that stuff is an eye, nose and throat irritant
 
P0420 code is not a bad cat, it is catalyst efficiency below threshold. This usually means the O2 sensors are headed south or the cat is contaminated. Grab a bottle of cataclean from the parts store and you'll probably see it go away.
 
Cutting off you pecker won't stop you from needing to pee, just saying.;)
 
ChiTown said:
How much power do you think you'll get from this mod? Enough to warrant the money spent and possible inspection issues?
Click to expand...

Zero if the cat is good, if it's plugged up, who knows.
 
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