So, Ive been searching both local and online for someone who can make me some cat-delete pipes, and I havent had any luck. The best answer Ive gotten so far was from a place semi-local and one place a "maybe", but Im not going to ship my parts across the country for a "maybe". So, I decided to tackle this myself. Now, bear in mind that the part I used to replace the cat is NOT mandrel bent, and is NOT stainless steel. This is simply a mock up, and the semi-local place that does this stuff all the time simply told me they couldnt scan the part to make a new one because the housing was too big. So this is just a "temp" part, if I like the way it sounds and performs I will send the parts off after Im done fabricating I will send them to that place and they will scan my custom made part and re-fabricate the entire thing but in mandrel bent SS. Also, the rest of the system is stock for now except for the rear muffler was deleted before I bought the car. My only concerns are that it will be too loud without the cats, so I intend on going with an aftermarket "cat"-back exhaust with a rear muffler to combat the noise (if it is too loud). Anyway, on to the pics, and, it is only tacked up for now until I have both sides fabricated and test fit, then they will be welded, painted with high temp paint, and installed for a while to test it out.

Also, I am no exhaust guy, I am an industrial Pipe Fitter so this inst exactly my forte, but I do know the proper way to cut/fit/weld any kind of pipe/tubing. I am TIG welding all seams, any excess penetration will be sanded smooth for maximum flow since its not a mandrel bent part. I am using 309 tig wire in case any one is wondering, Im not sure what the stock exhaust is made out of but it is very attracted to my magnet, so one would believe its just carbon steel but Im using the 309 to cover any possibility of a hybrid metal. For what it is Im sure it will work just fine, and its temporary anyhow.

 

btw, I guess in those pics I didnt have it tacked yet, thats why it looks off a bit. I'll get some better pics tomorrow of the other side and of both installed for the initial test fit on the car after work.

 

Why is it so hard to find a shop to do this? Is it a liability thing?

 

Good efforts! Hope you find just the right combination for yourself. Good to see a hands-on person doing fun projects! Keep us updated on the progress and on how you can live with the extra loud sounds.

 

Because it is illegal! You're basically removing the majority of emissions control equipment on the car, which is there for good reason. See Section 203(a)(3)(B) of the Clean Air Act of 1990.

It's not that hard of a concept to understand. It's about as easy as learning to put on your shoes...

 

In the early days it was pretty simple to remove the cats and increase performance. It's not that easy any more and as mentioned it's illegal and if you have emission checks yearly then you will not pass the visual inspection and the running test. Just read up on the function of the cats in todays cars and it will demonstrate how integrated it is to the engine performance. I would tend to go for a performance type cat which still allows the system to function correctly even with SW upgrades. Even with the cat bypass I would at least weld in a bung or 2 for the O2 sensors. It will be interesting to see if you get any improved performance and if it will run correctly without the downstream O2 sensor. You could also put a piece of black tape over the MIL.

 

After my exhaust debacle, no way would I try to remove Cats on this cat! I hope it works for you and will watch this thread with interest.

I'd think you'd get a Christmas tree full of warning lights...

In my state, there is no real visual inspection for cats; they plug into the car and read the values... that is it. If the car is older than that, I think you can do whatever you want. They use to put something into the exhaust, but I think that has been deprecated.

 

It will be .... loud ...

 

Thanks for the green law update, councilor but, there is nothing illegal about welding two pipes together.

You take the cats down to Bob at the local fab shop. Say “Hey, Bob! Can you make me a pair of these things minus all the crap in the middle?” Bob says “Sure”.

Pay Bob some $$$$ for his excellent workmanship and attention to detail.

Bob hasn’t modified anything. For all he knows, the pipes he made will be used as wall art in my garage. I know at least 8 different Bob’s around here. To use your words – it’s not a difficult concept to understand.

Besides, if you’re really concerned about the ethical and legal implications of modifying an exhaust system, you should probably direct your anger towards the OP who, is not only actively engaged in that very process, but sharing his progress via the internet as well.

 

I'll be interested in your dealings with the CEL ...

 

We call it a test pipe up here but the muffler shop can't install it. Also we have to change back at inspection time as there is a visual inspection as well as the normal plug into your OBDII port and check for codes. So far we don't get the sniff test at the tail pipe but my bet is it will come.

 

An indy shop can.

 

Rob Ford, Mayor of Toronto has one of those. Oh, wait. His is a crack pipe.

 

Secondary O2 sensors will be located as far downstream as the wires will allow, if that does not prove effective for the CEL's then I will be using some of bigdaddiesgarage mini-cats. Once these prototypes are made the shop in Des Moines will make me some nice stainless "test pipes", and these protos that Im making will be cut back apart, cats re-installed or a suitable aftermarket high performance cat will be put in instead. Then I can put in the "test pipes" for "off road use". No emissions testing here in Iowa, certainly not at the drag strip.

 

I have those but cannot put them in until July 3rd. My exhaust guy made my HFCs "exactly" like the stock ones and there is not enough room for the O2 sensor extensions. He will have to cut the existing tubes off and place them further out to install bigdaddies mini cats. CEL is showing bank one lean so he mused that even the mini cat may not fix it and that the reduced back preassure on the pre O2 sensor is meassuring too lean as the gasses pass by too fast and that a tuner would have to enrich my tune ....

 

Seems like that issue could be solved with a better/different 02 sensor. If the cause is the gasses passing by "too fast" then enrichening it doesn't really solve the problem unless you are actually too lean. Have you tried different sensors? Or at least a new sensor? I install an additionall bung to allow for a wide-band O2 that you can monitor before changing fuel tunes. Let me know how your quest goes

 

If someone how you change the trip value for the O2 sensor if you think everything else is good.

 

Just an update, the car is EXTREMELY loud now without cats, and locating the sensors as far back as I could I'm getting the codes. Ordered some of the cel fixers from bigdaddiesgarage so I'll let you all know if that solves that problem. I'm also making a bit less boost now, about 1 psi down but the car feels just as quick. I am going to get an x pipe put on and remove both silencers and put the factory rear muffler back on and see how I like the sound of that

 

Yep, I could only imagine... but the question... is it faster..? can you fell more hp?

 

well I cleared the codes and drove it some more, about 20 miles, codes havent come back yet. Still going to put the bigdaddiesgarage cel fixers in when I get them. I cant really tell if the car is faster or not, it doesnt seem like it though.