I think the smaller parts are pre cats its the big part that's the actual cat.

I could be wrong I don't know the v6 or v8 setup to well 00DakDan should know this.

You may be able to just cut the cat out

 

Well I know it's California emissions with what the service manual is calling "2 mini-catalytic convertors" and 4 O2 sensors, one before and one after each mini-cat. That big thing just before the muffler is the actual cat. I bet I could cut that bad boy out no problem and clamp in a new cat pretty easy.

Dan, if you are reading this thread do you think I am on the right track here? A new cat is a lot cheaper than the whole exhaust setup and I know I could sawzall the old cat right out.

Thanks for all the help on this one guys. I am learning a lot here. I thought those mini-cats are the actual cats.

Jimmy

 

OK here's another thought...My truck is way beyond warranty. We do not have any kind of emissions testing here where I live. What if I were to cut the cat out and clamp in a piece of exhaust pipe? I wonder how that would work and I also wonder if the CEL would go out or would it stay on constantly of I had no cat at all?? I don't know much about it but I have heard of guys "gutting the cat"...How do you keep the PCM from throwing a code when you have no cat??

Jimmy

 

1. If the PCM is throwing codes with the tri-cat setup, it's the mini-cat that's giving bad readings.

2. Servicing the mini-cats is significantly more of a PITA than the main cat

3. You could theoretically replace it with a straight pipe

4. The code will stay there, because no cat is worse than malfunctioning cat

5. The cat-delete dakotas are either pre-00 in which you could zip-tie the downstream to the frame rail, or post-99, which most people just mount it in a bung that is raised 1 or 2 inches out of the airstream, so that the O2 gets some exhaust gasses, but not all of them.

 

Thanks for the info Magnet. I guess I will be buying that exhaust assembly from Rock. $383.00 shipped, is not that bad a price when you consider all the pieces it contains. Rock is the only place I could find that sells the one I need. I might check with a good you pull it yard I have here, they might have it cheap but still in good shape. I know nothing about exhaust, as you can tell. Is it OK to use boneyard exhaust parts?

Thanks.

Jimmy

 

grab a sizable screwdriver, climb under your truck, and tap all 3 cats.

Usually when they fail, they make a horrible rattle.

 

I found a good site for checking codes, www.enginecodes.com. At least I thought it was very helpful, it provides info and suggestions of what to look for to fix each code. P0432 is the code for Main cat below threshold. P0423 is the code for a heated cat below threshold. I believe the main cat in front of the muffler is bad. If the mini-cat was bad I should be getting the P0423 code. I am at work again today but soon as lunch rolls around I will go out and smack the main cat, see if it rattles. I believe the main cat is the problem and will replace it tomorrow.

Jimmy

 

There were no rattles from the main cat, none from the mini cat either. I do not know how to fix this yet. I need to read my FSM again when I get home. I appreciate the help if anyone has any other ideas or input on this. I am coming up short so far.

Thanks

Jimmy

 

Like Magnet says, it's the upstream (mini) cats that are throwing the code. There are no O2 sensors downstream from the downstream cat to determine efficiency.

P0423 is bank 1, P0432 is bank 2

 

Agreed. I thought about that today, there are no sensors near the main cat, so the PCM has no way to tell whether it is working right or not. Plus the PCM has to be reading the O2's for the smaller cat because the code is for the Bank 2 cat. I will get with Rock Auto either tomorrow or Monday and order the exhaust/cats assembly. Rock is the only place that I can find that sells it. Magnaflow makes one but I'm not paying their price. Just for giggles I will call around tomorrow and see what a shop might charge for the job. I did not have time to check on a junkyard exhaust so just to satisfy my curiosity I will check on that tomorrow too. I really do think it would be best to buy new parts on this one though. I can order from Rock and have it here by next weekend. Will probably wait till the following weekend to swap it out though, Veterans' Day is Nov. 11th, it's a Monday and a holiday for me. I will probably need the extra time to get this done.

Thanks for the help on this. I wish the fix would have been easier and cheaper but it will be OK.

Jimmy