2nd Gen Non-Engine/Transmission Need Info on the Cat Converter

[Mike Ellis]

I am currently spending some bucks on getting my Dodge spruced up, and as part of that I have been contemplating at long last bombing the engine a bit. I have kept it stock all this time and tried to be a good boy when it comes to emissions etc.

However, I was looking at the odo and it is hard for me to believe that the cat is still functional approaching 200K miles. Hence I need some wisdom from my fellow TDR-ites, you're an R-ite bunch of guys in my book no matter what those other folks say :-laf

1. How long is the cat supposed to last?

2. Is it possible to buy a replacement that will work with higher flow pipes? More importantly, is it worthwhile to do so?

3. Anybody had any issues with emissions during inspections etc after taking the cat out?

I don't see much purpose to leaving it on there if it isn't still working, but I don't want to break the law either.

 

[DPellegrin]

If you remove the CAT you will be breaking the law. It's called "tampering" with emission controls. Now it's the enforcement of the tampering law that comes into question. Over the past several years I have only heard of a couple of large fleets that have been "busted" for tampering with the emission controls on their diesel engines.



The CAT on this engine is an "oxidation catalyst" . At 200K miles it not as active as it once was, but I'm sure it still reduces HC and CO gases. CFR 40 Part 86 requires emission system durability for 290,000 miles (I don't know where they got this number), even on diesels.



Regards,

 

[vssman]

Do you really need the CAT to pass the test? Well that depends on the type of test and if there is a requirement to physically check. In CT, the test that I have is one that the truck is on rollers and run at 30mph. They check for particulates (opacitly) and I have no problem at all in passing. I believe my limit is 20% and I run around 1%. Some states have a physical check to verify that the CAT is in place. If you remove it, save it in case you need to put it back. If you want, you can also run the pipe through it and weld the CAT back in place.

 

[DPrew]

I'm down the road in Buda just south of Austin. My cat unit went in the trash years ago. I don't think there is any diesel emissions testing in Texas. Even in Austin where the gassers get emissions testing I think the diesels all get a free pass. I guess if you want to be as green as possible you had better leave your truck close to stock. I've double the power output of my 02' but I'm sure my emissions are more than double the stock level.

 

[Alphacowboy]

Mike I dont know if I would be worried about it. Majority of the 2nd Gen's didnt have Cats anyway. I would say leave it alone as long as its not rusted out, if its rusted out, replace it with pipe. I would guess most emission places dont even look for a Cat on the 2nd gen Dodges.

 

[Dave M]

I have a 97 dually 5spd just like yours that I bought from DFW Texas area about 4 years ago. I removed the cat with the whole exhaust and put a 4 in MBRP turbo back exhaust with flow thru muffler and saved the old exhaust just in case. I then pulled the old air filter system with box and replaced it with an AFE open high flow air filter and box.



It improved the power (more air in + more exhaust out = more power) and I love hearing the turbo whistle now. Add some gauges and a #10 plate + 3K GSK (I have the parts waiting to install) and up timing to 16* and this truck will really be fun to drive. What are you waiting for... in my opinion. I wouldn't go back. All it takes is $$$$.



Dave

 

[Mike Ellis]

Thanks guys. My planned setup is the same as Dave M's, many folks have put in the same over the years with great results.

 

[Dave M]

There are many choices to pick from for an exhaust setup. Take it from me, you won't get the old exhaust off without cutting it and and at least twice. The original exhaust clamps crimp the pipes together so they usually must be cut. I tried to pull my off and gave up and then tried a hacksaw... forget it... then the sawzall made short work of it. When I put the new pipes on I went to NAPA and got 3 stainless band clamps for around $10 apiece. I've had the exhaust off since and its much easier with band clamps.



My experience is just with MBRP and I can say it fit very well. I would consider T305 over T409 stainless if you want it to look good sine the T409 gets brown looking and pick a 5 in stainless MBRP tip (I did) and it will really look good.



The best price was from Xtreme Diesel Performance - XDP Diesel Performance Parts because they shipped free.



Good luck and let us know what you pick.



Dave

 

[Vaughn MacKenzie]

2. Is it possible to buy a replacement that will work with higher flow pipes? More importantly, is it worthwhile to do so?

If you did want to install a 4" system with a cat, check with any of the shops that install diesel exhaust systems and see if they got one off a 600-series Cummins lying around. Last time I was at NW Custom there were a couple of them in the scrap pile.