Custom exhaust?

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I'm sure the info is around here someplace but to be honest, I can't be bothered to search high and low. I need to fix my exhaust as it is rusty and leaking and 2 deaths in the family this week have me exhausted... Pun noticed but not intended.

I guess the question is, if I do a custom exhaust without dual cats and O2 sensors, will the truck run normally? I know I will get cel, but don't much care. I can do a single cat and probably keep the O2 sensors, but would just prefer to eliminate all the BS.

Thanks for your time...
 
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I'm sure the info is around here someplace but to be honest, I can't be bothered to search high and low. I need to fix my exhaust as it is rusty and leaking and 2 deaths in the family this week have me exhausted... Pun noticed but not intended.

I guess the question is, if I do a custom exhaust without dual cats and O2 sensors, will the truck run normally? I know I will get cel, but don't much care. I can do a single cat and probably keep the O2 sensors, but would just prefer to eliminate all the BS.

Thanks for your time...

I don't think it will run right without the o2 sensors... you could do o2 simms.
 

CycloSteve

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Have a single high-flow CAT installed with the O2 sensors installed fore and aft. Your rig is OBDII and the ECU needs a proper signal from the O2's or you will have fueling, mileage and potentially engine damage from running too lean or too rich. Modern CATs work very well, and will not hinder your rig in the least.

:cheers:

Steve
 
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I was kind of looking into this before. Now I'm by no means an authority on this, but this is what I gathered from my mud/google searches.

The first O2 sensor is before the cats, that is what the computer uses to determine how the truck is running. The second O2 sensor is only used to check if the cats are working properly. There are several O2 sensor simulators out there that generate the proper signal of a working O2 sensor. So you should *in theory* be able to remove both cats, splice in that simulator in place of the second O2 sensor (the first one you need for sure), and it should (could? :) ) work.

I had ordered one of those sims off some guy on ebay in the winter, but it never ended up at my parcel place, or they lost it. And I haven't looked into it too much since.
 
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The ECM relies on the O2 sensors to adjust its fuel/air mixture, so you would not want to just get rid of them, and in the scheme of the cost of all new exhaust, it is not much more. You can use the old O2 sensors if they are in spec.
 
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Thanks for the replies. I will price out a hiflow cat and a sim, and see what is better for me. No emission tests in my area, (yet) so I guess either option could work. O2 sensors are pricey I guess... Hope mine are ok!
 

inkpot

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Thanks for the replies. I will price out a hiflow cat and a sim, and see what is better for me. No emission tests in my area, (yet) so I guess either option could work. O2 sensors are pricey I guess... Hope mine are ok!
Howdy! We DO have smog testing here, similar to California. I had my system replaced with one high performance cat, tucked in up high, and a flowmaster muffler. Now I can actually hear the motor running. That's something I have always had on my rigs in the past. I had the original ox sensors replaced in the same positions before and after, and they work just fine. I passed smog with no problems, and it runs just fine. Been like this for a year. and I am still very happy with it. John
 
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Thanks for the info guys! I look up the magnaflow cats, and I think stock exhaust is 2.25", so the 54955 is the one for me I think. I would guess from the part number that you are running 3" exhaust wspastorbryan? Or did you just sleve up to the 3" cat? The one I found in 2.25" says it is ceramic honeycomb for 4500 lb gvw. Would this make a difference? Why would magnaflow have a gvw rating on cats?

inkpot... How loud is your exhaust with the flowmaster? I really don't want any drone. I like it quieter as when we tow our trailer up mtn passes it gets loud in the cab. I found most flowmasters too loud in the cabin on my F350 and Tundra. Which series are you running? I might look for a freeflowing stockish sounding muffler. Any ideas on this?

As always, thanks for the help...
 
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I stepped it up to a 2.5. I don't know why I posted for a 3inch. I'm not sure on gvw, I just know that it's a three way and doesn't throw codes, so it runs really well.
A flowmaster is great, but if you want a little quieter, I have a Gibson on my wife's expedition and she likes it.
 
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Thanks for the info guys! I look up the magnaflow cats, and I think stock exhaust is 2.25", so the 54955 is the one for me I think. I would guess from the part number that you are running 3" exhaust wspastorbryan? Or did you just sleve up to the 3" cat? The one I found in 2.25" says it is ceramic honeycomb for 4500 lb gvw. Would this make a difference? Why would magnaflow have a gvw rating on cats?

inkpot... How loud is your exhaust with the flowmaster? I really don't want any drone. I like it quieter as when we tow our trailer up mtn passes it gets loud in the cab. I found most flowmasters too loud in the cabin on my F350 and Tundra. Which series are you running? I might look for a freeflowing stockish sounding muffler. Any ideas on this?

As always, thanks for the help...
3" is too large for these trucks unless you're running a turbo charger at 11+psi of boost. If you're on a naturally aspirated engine, SC'd engine 2.5" is the way to go. A single cat will work fine to keep the ECU happy and pass the "sniffer" portion of emissions tests.
 
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yeah i too am looking to get custom exhaust done. Mine is fully rusted and all the joints on the cat are filled with exhaust filler to keep from leaking. I am looking to help with performance a bit for going out on the beach..deep sand. I am pretty sure the cat is factory org. with 197k on it. The bolts dont even have heads..it also has factory mufflers. The engine still runs strong and pass compression check with flying colors. But this weekend on the beach in low it was having to still turn 3k rpms to keep going..idk if that is bad for an LC or not..and again this is in deep sand. Will a full exhaust change out help with power for the beach at all? Also what sort of bolt on easy power adders could help me out a bit if at all?
 

Lka1988

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You want sand tires for sand use. A free-flowing exhaust isn't going to net you much in deep sand, only get you into more trouble (revving more, digging yourself deeper, probably stuck).
 
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I have BFG all terrains right now..i mean its not like every week..just 4 or 5 times a summer. It did a lot better when i aired the tires down to 15-20 psi
 
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I have BFG all terrains right now..i mean its not like every week..just 4 or 5 times a summer. It did a lot better when i aired the tires down to 15-20 psi

That is step one with a big truck on sand.....air down!

My 4runner would totally bog in the sand on 33's at street pressure, Drop them to 15psi and it was a dream on the sand.
 
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I just did mine, and it doesn't hurt to have that o2 sensor in the back, but it would if you took out your cats. I would be worried about clearance too. Get a small 3-way cat, the magnaflow I have doesn't throw codes. This one is awesome. MagnaFlow 59906 - MagnaFlow Universal Spun Catalytic Converters - Overview - SummitRacing.com

So discussion of the exhaust "whistle" has been going on on ExPo for a few days, and someone has mentioned that the oem exhaust is stainless. How did you attach the magnaflow cat to the factory "Y" pipe? I planned to weld it, but my fab skills fail in the "can you weld stainless to regular steel" dept... Anyone??
 

LandCruiserPhil

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So discussion of the exhaust "whistle" has been going on on ExPo for a few days, and someone has mentioned that the oem exhaust is stainless. How did you attach the magnaflow cat to the factory "Y" pipe? I planned to weld it, but my fab skills fail in the "can you weld stainless to regular steel" dept... Anyone??

There was no problems welding during my recent exhaust remodel.

Before and After exhaust <link
 
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I got the cat and new section of pipe in yesterday. No drama except my friend used up all my blueshield so I had to use fluxcore. It got super windy, so that was probably good anyway. No leaks, and quiet! I'll post before and after pics as soon as I find the sync chord for my iphone...

Thanks for all the help!
 

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