I want to cut my cats off

[JohnnyJ]

So I was thinking about cutting my cat converters on my 04 1500 4.7L but have a few questions. Should i cut them off and straight pipe them or buy some high-flow ones? if i do cutt them off will it throw a o2 sensor code? has anyone had any experience with this? im getting Cat converter eff code on my truck and figured i would just do away with them. also getting a lot of condensation out my tail pipes and vapor on the right side. i know its not head gaskets cause i just replaced them thanks for the replys

 

[Beauregard7765]

If you run no cats and straight pipes you would have no back pressure at all which would kill performance. I believe it would throw a code since you wouldn't have a place to put a o2 sensor but not 100% sure on that. but I would put a new highflow cat and that should be enough backpressure to run it straight the rest of the way.

And water in the exhaust is perfectly fine. water coming out of the tail pipe is a natural occurrence of the combustion process. You will usually see it coming out of the tail pipe when the engine and exhaust system of the vehicle is not completely warmed up. When it does become completely warmed up, you won't see it any more, because it comes out as steam, but if the engine is already hot then its a problem somewhere

 

[JohnnyJ]

My bad I didn't wright that right right. I would straight pipe from where the cats were to the flow masters I have. Would that create enough back pressure?

 

[Beauregard7765]

Any muffler of flowmaster would be enough back pressure, unless it is the flowmaster 10 then it is iffy

 

[JohnnyJ]

There the flow master 60 series. So it would be good to cut the cats and and straight pipe them to the flowmasters? Besides the whole o2 sensor problem? Could I make a whole in on of the straight pipes and put the o2 sensor and and everything be good? Or would it make the pcm go crazy and loose power?

 

[blackbeautyhemi]

It'll def throw a code if you don't run any cats

 

[CorDog009]

Any muffler of flowmaster would be enough back pressure, unless it is the flowmaster 10 then it is iffy

Those are the ones I have, with 2.5" TD's I seem to have enough back pressure. No loss of low end torque and it still screams on the top end. I'd cut them off, or do like I did and cut them off, gut them, and have the empty cases welded back on so it still looks like you have cats. I kept getting the check engine light every now and then because the rear o2's were throwing codes (obviously) and did the old spark plug non-fouler trick (with steel wool packed inside ahead of the sensor). I used 2 per side, drilled the first one out with a 1/2" drill bit to allow the sensor to pass through it and into the second one where I packed some steel wool (I read to do that somewhere and I guess it worked, no code since then).

 

[CorDog009]

There the flow master 60 series. So it would be good to cut the cats and and straight pipe them to the flowmasters? Besides the whole o2 sensor problem? Could I make a whole in on of the straight pipes and put the o2 sensor and and everything be good? Or would it make the pcm go crazy and loose power?

The computer will be seeing that the rear o2's and the front o2's are reading the same since the cats won't be there and will throw a code saying that the cats aren't doing their job. That's the purpose of the rear o2 sensors...to keep tabs on the cats and let the computer know they're doing their job. The front o2's control your air/fuel mixture. On other vehicles I've had the rear o2's turned off in the computer, or ran o2 simulator boxes that tricked the computer into thinking the cats were there, but they were $150-200 if I remember right. I'd spend $10 on spark plug non-foulers at any parts store and call it a day.

 

[JohnnyJ]

Yea im gonna try that thanks for the replys

 

[homeguy]

Here's a video of a buddy of mine that cut his cats out and made a cheater. http://youtu.be/VTY91MEGTac


Sent from my iPhone using Tapatalk

 

[X Gixxer 1000 X]

I would not do that on a 4.7. You need all the back pressure you can get on that motor. If your looking for loudness I would cut the muffler completely out of the mix but leave the cats.

 

[aks0605]

I would have to agree, I wouldn't cut the cats. if replacement is what you are looking for then I would lean on a magnaflow Y pipe and HighFlow cats. The highflow cats should give you some pep to 2nd gear as well. Its kinda like balancing chemistry equations lol if you go wide open on the cats then use a dual chamber muffler as opposed to a single chamber or a full through muffler. If you go with the y pipe and highflows then you can be less restrictive on the back end. I am running an Aero Turbine 3030 XL on my 2006 4.7 with factory cats and Y pipe, no complaints.

 

[mrbigbill]

Been down this road....so let me explain, yes, truck will run a LOT better if your cats are even partially fried, I had an 04 that would fall on it's face at WOT, found cats partially plugged, like you, straight pipe was answer, so did......now the negative effect, truck ran amazing after removal, full power restored to the before anemic 4.7, honestly felt like a new truck, mpg rose, low end torque came back and accelerating on ramps like ease.......dodge is a strange beast, they use ALL 4 sensors to set short and long term fuel trims, with semi plugged cats fuel trim tables looked horrible with scan tool, each bank was fighting it's twin.....so cats gone, fuel trims look more even but running fairly rich, motor breaths easier, watch your mpgs and as soon as they dip go in and wipe long and short term fuel trim tables....about once every 2 months for me and she'll run just a tad rich but run fine.......also, the 545rfe trans is a "learning" trans so after you dump cats, do a trans relearn to adjust pressures to higher torque.....yes, you'll get CEL for cat efficiency and possible bank 1/2 rich.....but she'll run like you've never felt her run......also, in a pinch you can unplug intake air temp sensor and it'll default computer to thinking temp outside is below zero and start pouring fuel down it's throat (think track times).......hope this helps, dodge cats suck butt crack

 

[HemiLonestar]

Considering after 7 years and an OP who hasn't been seen since the day after the original post was made...................I think a decision was made lol.

 

[Lyle Longboat]

Was going to say……. A few years later on this one