I removed my cat on Friday. Holding it up to the sun and looking through it I could only see 2 small circles of light.....very small. It's a 06 with 90k miles, dont know if it always looked like that or if it's real dirty/cloged. I then replaced the muffler delete with this one. It took the nastyness out of the straight pipe sound but still sounds great. It's only about a foot long and is straight through. I've noticed significantly stronger sound, lower EGT's, thicker and darker looking smoke, and a bigger grin on my face. Wish I did it sooner.

 

Holding it up to the sun and looking through it I could only see 2 small circles of light.....very small. It's a 06 with 90k miles, dont know if it always looked like that or if it's real dirty/cloged.

It'll look like that brand new, just go by any muffler shop and ask to see a new cat. and look through it the same way. Same outcome as your old one. Then see if they have a high perf. version, the holes will be 'slightly' larger not by much.

 

If you have to pass emission inspection, then removing the cat is not an option. AND, just because you don't have to pass it now doesn't mean anything for the future. The tree huggers grow stronger with each election. My '04 didn't come with one.

 

On the part where you state on inspection, TRUE. they can't go to past vehicles that didn't have the equipment. I don't think they can include any vehicle in the past, when a law is passed it's usually that date forward. The past is the past.

On these 6.7 with the smog equipment, do those need to be 'smogged' like gas vehicles?? If so, no gov. can have older ones with the 5.9's to be smogged.

I hope the heck not. I'd hate to be living in that day, the tree huggers would have too much power.

Ask a tree hugger who's driving a hybrid or electric where are all the dead batteries gonna go after it's been recycled too many times already???

 

I wonder if I could take the cat out and replace it with that little muffler from Dynomax? I mean, could I put it in the same spot as the cat? I already have a muffler delete. Or would I have to take the cat out, put a straight pipe in its place and then put the muffler further back? Scotty

 

As it's against Federal law to "tamper" with the emission systems, then I disagree with you about laws can't be retroactive. I know in Tennesse, when the emission inspection requirement was implemented, a vehicle that came from the factory with a cat was required to have a cat to pass. That's the first check done. No cat, no further test. You fail. I didn't matter that you had removed your cat and punched out your gas filler neck restriction so you could run on cheaper leaded gas. Your vehicle HAD to have a cat and pass a tailpipe sniffer test. Cost some people good money to have cats put back on.

I have no idea what you mean by this statement: "On these 6.7 with the smog equipment, do those need to be 'smogged' like gas vehicles?? If so, no gov. can have older ones with the 5.9's to be smogged."

My '04 Ram must pass the emission test so yes, a "gov." CAN and does have5.9 and 6.7 diesel Rams emission checked. Tennessee law requires ANY vehicle newer than 1973 to pass an emission test unless it's a diesel with a GVWR of over 10,500 pounds or a motorcycle. '96 and later vehicles get a computer plugged into the OBD port, a visual for a cat and a fuel cap test. 95 and earlier vehicles get the same visual check for converter, gas cap check and a tailpipe sniffer test. The standards the vehicle is checked against are those for it when it was manufactured, not current standards. I've never been asked about no cat on my truck so the computer knows what came on the vehicle and what didn't.

These provisions are for the Tennessee emission inspection program. Programs in other areas may very well be different as well as any future required programs. I now the Tennessee programs complies with EPA requirements. You can be that with the tree huggers getting stronger every day, especially with the just completed election, things will change. JOIBO!

 

We have to pass emissions where I live in colorado, but I was curious if our trucks would pass emissions without the cat in place. Like if you hollowed it out and ran pipe straight through? Anyone tired this?

 

You have to go on the roller like a gas vehicle?? I haven't been to a smog station in yrs., been trading in vehicles before I need to get them smogged. Last I heard was you had to put the vehicle on rollers like a dyno except it was to check emissions output.

Here, I don't have an inspection let alone have to pass an emissions test. I did keep my choker though, I think I'll knock out a 5'' hole and run a pipe through.

 

Have not myself. Does your emission inspection involve hooking up to the OBD port or is it a tailpipe sniffer test? If a sniffer, I doubt it would pass. If the OBD, then it would depend on whether the OBD has the capability to detect the fact that the cat has no backpressure. Try it & let us know. I probably shouldn't be posting on a cat issue as my '04 didn't come with one.

 

In Utah, depending on county, you have an opacity test. They put the truck on rollers and essentially test it at cruise and than take it to wot. If you fail the percentage of opacity = no go. They do check for cats. My 96 came with one and so I had to put it back on, glad I kept it.

I think it is actually stricter than California, dad and brother don't have any type of test.

 

I think we have the opacity test here too. Do you think our trucks would pass that with a hollowed out cat? That way it would pass the visual inspection, but would it pass the opacity test without the cat?

 

They will pass... I have a friend that was worried about the increase in sound without a cat but the inspection guys don't seem to care.

Don't ask, don't tell? But yes they will pass.

 

I'm going to straight pipe mine and put the cat back on for the smog test. We don't have random vehicle inspections in Nevada so I'm not too worried about it. It's not that much work to R&R a cat once a year.

 

Nothing sounds better on a 5.9 than removing the muffler and leaving the CAT on. I thought mine sounded better than any of the aftermarket systems I had heard. It sounded just like straight pipe but only 2/3rds as loud.
I have a 5.9 CAT that I am going to put on my 6.7 to try to make it sound better and also to fool any LEO that may look under my truck. I have removed all my emissions junk and I just don't like the way the truck sounds now.....