I bought a 96 Dakota Sport with 318 about a month ago. It has a flowmaster exhaust that's a bit rusty and doesn't look like it was installed anytime recently. I didn't notice there's no cat until after I bought the truck. I looked it up and the truck last passed emissions in January 2015 in CT, my home state, so it's due again next January. Is it possible the truck could've passed CT emissions without a cat? I haven't gotten any check engine codes. There's also an 02 sensor behind the muffler as well as in front, which I thought was odd. Any thoughts?

 

Well, the secondary O2 just looks for a different stream; the time delay going through the muffler probably takes care of it.

And yes, you CAN pass older emission tests without a cat, as long as the motor isn't burning oil, is in good tune, and is running right; the earliest cats were more there to keep the motor clean after some wear and tear on the motor occured.

I'd still consider getting that muffler replaced by a cat, and a new muffler put downstream; but that's me.

RwP

 

Actually, it shouldn't pass. Every state has an emissions law that all original emissions equipment must be present. Most states don't do pre-ODBII emissions testing as far as the amount of smog you're producing, but the equipment needs to be there if it was originally on the truck. Most inspection stations have a book that lists every make/model and the original smog equipment that should be present. Now, with all that said, it CAN pass depending on the inspection agent and their thoroughness.

FYI, I checked and CT requires an emissions test for your vehicle....Those that are exempt:

Model year 2013 and newer.
Model year 1991 and older.

Also

In addition to any or all of the tests below, all vehicles will undergo a Catalytic Converter Functional Check.
This test checks for the presence of a catalytic converter; without a catalytic converter, your vehicle will fail the emissions test.

All of this on CT DMV website.

 

Here in NC thry don't do emission testing on anything older than 96. BUT, they do check to make sure all factory installed smog equipment is present. Will fail visual if anything is removed.

 

If the back O2 was behind the muffler, they may have thought it was a cat ...

I dunno, I wasn't there.

(Could also be the inspector Just Did Not Care *grins* )

RwP

 

I've read the same (I'm also in NC)....What's not clear is what's going to happen with my 360 swap into my 90 Dak. It's a crate engine with carb from Mopar that of course had no smog equipment on it. The NC rules state that you can put a later/different model engine into a car but that it should have the smog equipment that came with it. So not sure what I'm going to do. I will install cats, because the truck had them (going dual exhaust), and I will install a PCV. But wondering do I have to set up some kind of EGR and do I need to keep the Charcoal canister? Since I'm going sans computer, doing a purge on the charcoal will be problematic unless I switch it to vacuum. And I have no clue how to do an EGR setup. I know many even later model guys eliminate the canister and vent to a fuel filter...Not sure what I'm going to do yet.

 

What one inspector told me was, it all has to be there, does not have to work, but it has to be installed.

 

Thanks for all the input. I'll probably end up clamping a cat on where the muffler is and putting the muffler in the back of the truck instead of the side. I don't know what exactly to do with the o2 sensors but I have a while to figure it out. Hopefully it'll pass and then I'll put everything back the way it was before
I like how loud my truck is right now and reducing power and loudness is no fun

 

High flow cat won't take away any power or loudness. If you have two o2 sensors, one goes in the front and one behind the cat. Only one, it goes in the front.

 

I wouldn't be advertising that you plan to break the law by removing your cats, not to mention youre ok with increasing pollution because you want a loud vehicle.