Questions about removing Cat from 2007 tundra 5.7

Hey guys, So tomorrow I plan on taking my truck to a buddy of mine who owns a muffler shop. He's gonna remove my cat because I think it is my main problem with my performance and horrible MPG. Thanks to you guys on here that pointed me in that direction.

First question if anyone has the time, How many cats do these trucks have? I can only see one, But I was only under the truck for a couple secs cause I usually have my son with me on my days off.

Second question, Can anyone confirm if the spark plug non fouler method works to remove the CEL after the cat/cats have been removed? I deff dont want the CEL to be on all the time. I have looked at some simulators that look similar to the non foulers on Amazon, But didnt know the best route to take on these trucks in particular.

Thank you for your time!

 

I’d suggest putting in some new cats. Can even get high flow ones. I tried the O2 simulator after I put headers on my 2010 and it never worked right and I’d always get a CEL when it got wet from rain or anything else.

Here is a pic of a 2007 5.7 exhaust.

 

Hey tim thanks for the pic, So by the looks of this I only have 1 cat? #4 is the cat right? In my state they dont do inspection and its also a budget thing at the moment. Eventually i would consider putting a new cat in. Esp if we ever decide to move up to NC.

I currently live in SC and apparently every truck on the road doesn't have a cat lol.

 

our trucks have 4 catalytic converters, each exhaust pipe has one before the O2 sensor and one after. I'm not a pro but I would say that if you're going to take cats out, you can only take out the 2 after the sensors without throwing codes

 

Dang, That's good to know. So that changes everything. I have had multiple guys I work with at BMW tell me that my cats are stopped up and I need to remove them and i'll prob fix my mpg issue and the performance issues im having at times. If I take out all 4 cats will it just be the codes thrown for it not being there? I've read on this forum somewhere that you can run arguably better without the cats.

If removing all 4 cats will only throw a code and change nothing else I can still find a way to simulate it and be fine with that.

 

If anyone can chime in and confirm, Can you remove all 4 cats and only have the CEL come on because the O2 sensors arent seeing the cats anymore? Or will it physically effect something in the exhaust and make things worse?

Once again thank you guys for your time!

 

#4 is the muffler. The cats are inside the boxes 1 and 2.

 

I don’t think it will go in to limp mode based on my experience when I had a CEL for the O2 sensor, but it will probably run bad by either running rich or lean if the ecu can’t monitor the exhaust.

 

Im really green on the whole process, I wonder if I apply the simulator will it act as if they are still there and trick it. If it is tricked shouldnt it monitor the exhaust the same way as before and give me the correct ratio?

 

I bet @dirtydeeds would know.

 

Dont do it!!!!!! The cats are NOT restricted in the tundra the flow really good. And oem cats are alot better than aftermarket. Whats your mpg?? You can remove the 2 cats those are secondary and wont set a cel. They are the furthest back.

 

I'm getting about 8.5 mpg man. I work with a couple guys who owned a mechanic shop and heard from other ppl that my cats are bad. It's all adding up to the cats. So I'm curious now, would the two cats your telling me to remove will that fix my prob if they are clogged?

How do I know it's not the other two that your telling me not to remove? What if those are the ones that are clogged? What consequences am i looking at other than a CEL light if I remove all 4. I've read on other tundra forums that I can literally remove all and nothing will effect my actual vehicle only a thrown code and apparently I can fix it with a simulator.

Honestly I just need more info before I can make a decision.

 

Yea something is going on here, that's not normally mpg for these trucks at all. You could be right about clogged cats. You can remove the back two cats and not get a cel. If you remove the front two well your going to get a check engine light. I would talk to the expert keith from dirty deeds he knows more than anyone.

 

You can remove all cats and put in a simulator and that would work but iv heard when it rains they get wet and sometimes dont work but maybe they fix that problem and your exhaust is going to pretty loud with no cats and the smell.

 

It's really a budget issue, and in SC I can somewhat get away with not having one. I would love to hear what Keith has to say. I really dont have any expierence with cats in general. I can deal with the sound I live in a somewhat rural area. I havent heard about smell though, What will it smell like?

 

your exhaust will smell rich.. you'll smell the unburnt fuel. that's what cats do, they contain heavy metals (like platinum I believe, which is also why high quality cats are so expensive) that get hot and as the exhaust passes through the catalytic converters, all of the fuel that wasn't burnt off during combustion in your engine gets burnt off as it passes through the cats. If your first set of cats were bad, I think you'd have an O2 sensor code already, because they measure the exhaust/fuel levels and if the first cat wasn't working, you'd get an O2 code (can anyone confirm this?) .. the second set of cats is probably just to make sure the exhaust is clean by the time it makes it to the back of your exhaust system.

My suggestion would be to remove your second set of cats if that's what you want to do, and leave them out. I wouldn't take both sets out but that's just me, you can do it and add a simulator but yes, your exhaust will smell of fuel. When it comes down to it, Toyota designed our exhaust system this way for a reason. I think you'd actually see gains in performance by removing the cats but personally I wouldn't do it myself

 

Hey I was wondering if you could guide me as to what would be the best option for me. My front roght cat is blown and rattling bad I want to delete 2/4 of them but most ppl don’t mess with the front set of cats. I had the dirty deeds guy tell me to remove the front set and put the rear 2 cats where the front ones where. Do you think this would work with all the o2 sensor stuff?

 

Would it be the same if I replaced my front cats with my rears ?