I have searched but i did not find exactly what i wanted. Can you take the cats off of an ls and not throw any codes. Im wanting a cheap way to let the engine breath a little more and maybe pick up some mpg's. I can do it myself i just want to make sure its not going to screw anything up. Its an 05 ls v8. I plan on adding magnaflows also. Keeping the rest of the exhaust stock though for money and bang for the buck reasons. Thanks.

On an otherwise stock car, it's not likely that removing the cats, if they're in good condition, will improve on much of anything.

KS

I do plan on doing a complet k&n intake and the magnaflows in place of the stock mufflers. Maybe eventuallyan sct. I do realize that after replacing the mufflers the cats are the biggest restriction in the exhaust system. If i can do it for 40 bucks worth of pipe or less and it gains even the slightest feul milage and performance increase plus help the sound a bit. I will consider it well worth my time. Not too mention where i bring my scrap i could probabaly get 15 a peice for the cats making it a very cheap mod. I just want to know if it will set codes or not, cause that would be a deal breaker for me. i hate cels on nice vehichles.

It will definitely throw codes. The vehicle is designed and optimized for a system with catalytics in it, and it is nothing like the 70's where they just tossed emissions crap on there that you could take it back off without repercussions. You will not gain anything other than more work by removing otherwise healthy converters.

On a side note...if you're only getting $15.00 per cat you need to go somewhere else because they're screwing you big time!

Thanks for the reply's. On scrapping the cats the place i go to is only 15 minutes away and i don't live close to any big citys. The last time i brought one in that size thats about how much i got. Scrap is up a bit now so it might be more than that. Its not worth it to drive real far just to scrap a coupl cats.

Next question is how do people with performance cats get away with not throwing codes? I have been under the car but didn't check real close at what sensors are in the exhaust. I would think that if you put performance cats in and if it has pressure sensors it would still say that its flowing too much.

The sensors are located before and after both cats---4 sensors---and test the amount of oxygen in the exhaust streams. You'd need to weld in bungs to the new cats ($5 each plus welding cost) to have a complete set-up.

KS

OEM cats are about $1000 each new from the dealer. $15 for scrap is getting ripped!

And I would agree, removing them WILL cause codes and will not benefit you in any way but sound.

Yea it probably is getting ripped off but the factory rips you off when they sell them. Next time i scrap some cats i might have to look around some more. If i put the sensors back in the exhaust if i take the cats out i don't see how the oxygen levels would change. I didn't think cats took oxygen out of the exhaust gas? And if you have ever took a cat off and looked inside of them you can see how they are very restrictive. Its a big honeycomb type deal.

Yea it probably is getting ripped off but the factory rips you off when they sell them. Next time i scrap some cats i might have to look around some more. If i put the sensors back in the exhaust if i take the cats out i don't see how the oxygen levels would change. I didn't think cats took oxygen out of the exhaust gas? And if you have ever took a cat off and looked inside of them you can see how they are very restrictive. Its a big honeycomb type deal.

catalytic converters don't remove oxygen from the exhaust. they burn off the other gases in exhaust and the sensors measure the amount of oxygen to make sure the converters are still doing their job. does that make sense?

catalytic converters don't remove oxygen from the exhaust. they burn off the other gases in exhaust and the sensors measure the amount of oxygen to make sure the converters are still doing their job. does that make sense?

Good simple explanation!

KS

Ok makes sense now. Thanks for the explanation. Its really appreciated. Im the kind of person that doesn't want to just be told you cant do it. I want to know why. Thanks again.

Looks like i will just stick with the stock exhaust and replace the mufflers with some magnaflows and do a cai.

Good simple explanation!

KS

Thank you. :)

Ok makes sense now. Thanks for the explanation. Its really appreciated. Im the kind of person that doesn't want to just be told you cant do it. I want to know why.

Yeah I know what you mean. I can be the same way :D

I don't throw codes on my 01'

Im getting ready to get my exhaust work done and did anyone that has removed cats in their car have to use a defouler to move the secondary o2's out of the exhaust path to trick the ECU into thinking the Cats are still there and functioning like normal. Or will i be fine putting them right into the bung?

I have never heard of it done on a Lincoln but I have done it on my f-150 and have done it on many Powerstrokes. What are you removing cats for? Header kit or just to make it stupid loud?

Nitrous and such lol

I have almost 148K miles on my '02, have the original cats, and have been spraying, and using a stand-alone methanol fuel system to go with the spray for about 50K miles. No suggestions of problems with the cats, and no codes either.

KS

Nitrous should be one of those bad words on here. Maybe if the motors built for it but not many if any factory motors are "met to have" Ni:q:q:q:qous!

Nitrous should be one of those bad words on here. Maybe if the motors built for it but not many if any factory motors are "met to have" Ni:q:q:q:qous!

'Ducky, I'm going to suppose that your comment was not meant to be as 'in-your-face' as it came out to be.

If you'll re-read my comment, just above, you'll see that I stated my use of Nitrous oxide and methanol over an extended period. During that time I set four land speed records at Maxton, NC with the car, and hold the fastest one (E/F CC) to this day.

If you are going to get real enthusiastic---200+ HP--- it's accurate to suggest that engine modifications would be wise. Please see the 'Land Speed LS' thread in the HP section. But I've successfully run a set of 150 pills during excursions at Maxton. And my experience with nitrous oxide, and methanol fuel goes back to the late '70s.

KS

'Ducky, I'm going to suppose that your comment was not meant to be as 'in-your-face' as it came out to be.

If you'll re-read my comment, just above, you'll see that I stated my use of Nitrous oxide and methanol over an extended period. During that time I set four land speed records at Maxton, NC with the car, and hold the fastest one (E/F CC) to this day.

If you are going to get real enthusiastic---200+ HP--- it's accurate to suggest that engine modifications would be wise. Please see the 'Land Speed LS' thread in the HP section. But I've successfully run a set of 150 pills during excursions at Maxton. And my experience with nitrous oxide, and methanol fuel goes back to the late '70s.

KS


Indeed it was not meant to be slander. I know there are lots of guys who use N20 as well as combinations, if you know how and have the proper set ups the stuff is quite amazing. But when some guys go to the spray to "quick fix" a need for power if you will. ( In many cases) its just not right. I have followed your threads in the past and would agree with you that, doing it right is very cool. Expecially when you have over 30+ years in playing with the stuff. Sorry if it sounded blunt.

Sean

Indeed it was not meant to be slander. I know there are lots of guys who use N20 as well as combinations, if you know how and have the proper set ups the stuff is quite amazing. But when some guys go to the spray to "quick fix" a need for power if you will. ( In many cases) its just not right. I have followed your threads in the past and would agree with you that, doing it right is very cool. Expecially when you have over 30+ years in playing with the stuff. Sorry if it sounded blunt.

Sean

:):):):):):):):):):)

Ken

I think there is something you can do with the sct tuners that allow you to have no cats and no codes either.

old thread revival...

Cats went bad on my 03 was throwing codes.

Unbolt from the collecters on the manifolds and the reap pipe assembly.

Get large metal rod to fit into pipe.

Bang out old cats till nothing is left in them.

vacuum out if you like.

Rebolt.

Took me about two hours to get it apart and back together.

Still throws codes but i havnt noticed any difference in fuel economy hovering around 22 or so around town and sounds throatier.

i just replaced the bolts and hardware to remount them for around 5 bucks.

It now has a noticeable increase in acceleration compared to having them in.

No numbers to prove any gains but for free im happy with the results =)

All recent cat cons have been designed so that they have at least the same flow capacity as the pipes to which they're attached. Unless the cat cons have begun to fail and plug up, there will be NO change in any sort of performance from removing them.

KS

^^^ Absolutely right, pulling the cats is nothing but a waste of time and won't improve performance a bit. They're on there for a reason.