Well, my cat is bad, I dont like my muffler, and I just want to start a new project and spend as little money as possible. I have been thinking about just cutting off my cat (already trashed the muffler) and putting a straight pipe all the way back. Will this cause any issues as far as running with no cat? I know it will throw the check engine light (already on), which brings me to another question..Ive heard about o2 sensors that "fool" the computer into thinking that everything is normal, has anyone tried these before? where would I be able to get one?

 

o2 simulator, you can make it yourself how are your electrical skills?

 

o2 sims are a waste of time. had one on mine and did more trouble then good.

Now i have a bad PCM due to it, and maybe some shorts along the way.

Best thing to do is ziptie the damn o2 sensor itself to the frame rail, and plug the exhuast.. SOMETIMES it can through a code, most of the time it doesnt.

Keep the front o2 sensor all it does is read the air to fuel.. so even if you dont have a cat it doesnt matter..

straight pipes sounds nice but you want some backpressure. Install a Single chamber muffler.. but running say 3" Straight pipes will sound nice... but hurt you in the long run unless your running some pretty crazy *** mods.

 

hmm, will keep in mind, Thank you.

 

Before you even consider a no cat exhuast system, you need to know what the consequences are:

1. Local and state laws prohibit such a modification unless it is intended solely for off-road use

2. Powertrain Control Modules rely on Pre-CAT and Post-Cat sensor readings to adjust Air/Fuel mixture to a nominal 14.2, and most sensor control groups will not function at allsuch EVAP, FUEL, and so on. The PCM will instead run at hard-coded values in an open-loop state,which will dramatically reduce torque and horsepower curves by 30%, as a safety feature to prevent engine damage.

3. You'll never pass inspection without a CAT Converter

I recommend you not go for a cheap solution but instead go for the most expensive over a long period of time. Start with headers (ceramic orsteel with header wrap), then a high flowCAT, 3" pipe Cat back, then a high-flow, low restriction muffler with a resonator exhuast tip.

My advice is to find a muffler shop and talk to the mechanic and discuss your options with him. I have a 02 Dakota R/T 5.9Lwith a $3,500 True-Dual setup that gave me an incredible 55hp gain at the wheel on a rolling dyno.

 

I'vehad a simulator on mine forover a yearand have had no problems. I got it from Jeg's,but you will have to make your own now if you wanted to go that routebecause the government went after the company that made them and shut them down.

 

1. Not all states require a cat on your vechicle... OK is one of them... if your headlights and horn work.. your good to go. Most states do require one though, but it isn't hard to get passed.

2. Are you kidding me? The 1/1 pre cat sensor has NOTHING to do with the cat itself.. so it woudn't rely on the cat to work. It read air/fuel mixture in the exhuast, the 1/2 post cat tells the computer if the cat is working properly, and if the cat goes bad it SOMTIMES tosses codes for it, simms help for awhile till they go bad and then throw codes, you can aslo tie the sensor to the rail.... and get no codes. Open loop actually dumps more fuel on throttle. Why do you think the truck runs a hell of alot better when you first start it up in the morning.. you can run rich and STILL produce More or = power. Not a 30% reduce did you pull that number out of your ***??? lol.. Post proof or dynos, becuase as many cars that ive seen get new exhuast and delete cats, not only does it sound better, but runs better (less restriction) and most of the time throws codes but can still get passed for a few extra bucks or a good hadheld.. o and your truck wont stay in open loop for deleting the cat. Open loop helps heat the engine to correct opperation temp and then will go to closed loop..

3. Ya you will, makes friends, bring an extra 50$ or reset the damn PCM before you go.. OBD2 emmsions doesn't do the exhuast sniffer, they go strickly by what the PCM says.. if no codes are showing it will pass...

Got any dynos for that exhuast system you put on? Cuz unless your have MAJOR mods done to the motor itself and was running STOCK exhuast and then upgraded to a set of headers, and a good free flowing exhuast.. I HIGHLY doubt you made 55hp. The best headers out there maybe give a gain of 10-15hp and the piping your lucky to get an extra 5 out of that. Proof or to me your Full of ****. As for your comments in your post right now i can tell you dont know ****.

 

What he said^^^^^ as long as there's no visual inspection like cali or texas (i think) then you should be good. As long as you're not throwing a code, you will pass the OBDII test no problem.

$3500 for an exhaust????? is it gold plated or something, holy crap, even with my headers added into the cost, its gonna cost less than $1300 for my true duals, that includes my pph headers, mandrel bent 2.5" pipe, x-pipe, and mufflers and tips, no cats. Hell you can get a whole spintech gsmsetup(headers and exhaust)for like $1600, now when you get it........thats another story.

 

$3,500 Ummm yea... ok.

 

if you paid 3500 for an exhaust you should shoot yourself in the face. you will not gain 55 horsepower on a 5.9 v-8 just by doing exhaust, it is physically impossible. maybe on like a huge diesel engine it's possible but not on a 360. i'd like to see some proof. however, to answer this guy's question. dont try to do any real in depth exhaust work on a 3.9. number one it's not worth it (because it still sounds like a v-6 no matter what you do) and number 2, most of the time you lose power if you go any bigger than 2.5 inch pipe. i'd say get your cat replaced and put a muffler of your choice on there and be happy. I once cut off my muffler and put a cherry bomb glasspack on my 2001 for the hell of it and it sounded like **** and i lost a ****load a power. I had to buy a dynomax catback just to fix the problem like 3 months later.