97LC Do toy need Cat Converters (1 Viewer)

[410225]

Is it necessary to have cat converters? Will it ruin or mess up the exhaust system? Here in MN, we do not have emission test anymore and my cat converter is making buzzing noise and I was thinking of taking it off. Will this be a harmful move?
Thanks

 

[moralien]

Do you need them? No but your engine will proboly pull codes without them. Just cut them out and have a high flow cat put in. Should cost you less then 200 bucks. You don't want to put oem's back in unless your into S&M.
Nick

 

[Adrian]

Do you need two or just one?

 

[moralien]

[quote author=Journeyman link=board=2;threadid=6142;start=msg49368#msg49368 date=1065752284]
Do you need two or just one?
[/quote]

Just one.

 

[NW-sickboy]

i recently did a cat back system (custom) mainly for clearance issues over performance and i went to one cat. the main issue is the sensors in front of and behind your cats. runs great and no crazy codes.

 

[Imagery]

How difficult is it to have a muffler shop cut off the sensors from the old cats and weld thel into the new system? If I take my High Flow cat to the same shop that did my Flowmaster 50 series, are they going to tell me I am crazy wanting them to cut out the old sensors and put back into the new system???

 

[NW-sickboy]

they shouldnt think you are crazy. i took mine to very reputable shop in boise and they just cut the olds out with a plasma cutter and put them in the new pipe they had ran.....might depend on the shop though.

 

[410225]

Currently, I see front and back cats back to back and you are saying I only need one cat? Also, where is this sensor located and will the custom shop know what to do when I bring my one cat and tell them to install for me?

 

[NW-sickboy]

yeah. get (or buy one from the same place that does the work) one high flow cat and they will replace it. it you look in front of the front cat and behind the rear cat you will see sensors mounted to the exhaust. you can't miss them. any good shop will know exactly what to do.

 

[yomama]

Darkangel,

I am in MN too. I had my two CATS removed and replaced with one HiFlow. A local shop did it. I also put on a HiFlow muffler, but next time...I will not put a muffler on. I have a turbo on mine and I have read that with a turbo, it does two things, burns more of the fuel and also acts like a muffler. I could try and get by without a CAT as well, but for sure it would mess with the ECU and set a code. I dont' like lights glowing on my dash....

Yomama

 

[410225]

yomama,

Where did you get your done? And what brand Cat did you buy from where?
Thanks.

 

[410225]

Okay. i am planning on buying high flow cat for 97 LC. Couple questions.
1. What is the inlet/outlet diameter? 2-1/2" or 3"?
2. Is it single in single out?
THanks for your help.

 

[Imagery]

I think it is 2 1/2 in and out, and it is single in and single out. I am thinking about getting the cat that MAF sells which goes with their turbo exhaust kit. My Flow Master 50 is single in/single out , center/center, and it is 3" diameter. So I have stock 2 1/2 pipes going in and out of the Flow Master. Ii probably would do the same for yhr high flow cat too, 3" in and out.

Mark

 

[yomama]

Darkangel,

I can't recall the name of the place off hand. I can look for the reciept.
It was located off Bunker in Andover. Yours would be 2 1/2. Mine was 3", but that is because the turbo out is 3". It then travels back to the CAT, Muffler and then to get between the frame and body it is reduced to 2 1/2 and then a Y pipe to dual outs making it look like a dual exhaust system. Sounds great and looks cool too. You can see the tips on my web page www.yomama.net go to "More Cruiser pics"

Yomama

 

[moralien]

Lets not make this harder then it is. You have 2 O2 sensors. Located in the black. have them cut out the offending material ( in between the black) . This can be accomplished with torch, a plasma cutter or a sawsall. It's not rocket science and any reputable muffler shop can do it. Tell them to put in a high flow generic cat. The diameter is not important as they will just match to your OD anyway. It's a 1 job for any good shop. It should not cost more then 200 bucks. I think I paid like 160 actually. And if your really cheap you can have them cut out both cats, un bolt em see which one is clogged. It will be like small honeycomb material. If you can see thru them there good, If you can't there bad. If you happen to have a good cat leftover just tell them to weld that one back. But this time instead of havening it run vertical have them weld it horizontal. Also a good tip if you have a generic put in. See below pic. Remember to keep this stuff simple. If you waste your time ordering a cat from somebody you’re going to have a harder time getting a shop to work on it. Find a good place to go and do everything there. They will be more accommodating. Don't be afraid to tell them what you want, remember it's your truck.
Nick

 

[Imagery]

Thanks Nick... You have made excellent points. Thanks for the picture showing your system. I think you are right about just getting a shop to handle the parts and install all themselves. That way they will absolutely be more accomodating...I've been down that road before. I guess one good quality high flow cat is as good as another, the point is to clear the exhaust path of any obstruction (i.e. clogged cat and/or muffler).
I'm going to stop by the shop where I had my Flow Master installed and talk with them about doing it and what the cost would be.
Thanks,

Mark

 

[sleeoffroad]

The biggest issue with removing the O2 sensors is the mounting system of the sensors at all. It is a machined piece with two studs on it. Normal US made cars you can just weld a new bung on and insert the O2 sensor.

With the 80 you have to cut that piece out, grind it clean and remove some metal to make it fit the new exhaust. Otherwise the tip of the O2 sensor is not in the exhaust stream all the way. Easy to do, but most exhaust shops just want to get you in and out as fast as possible, so it takes some time to locate a shop that will work with you.

 

[moralien]

[quote author=sleeoffroad link=board=2;threadid=6142;start=msg49678#msg49678 date=1065822805]
The biggest issue with removing the O2 sensors is the mounting system of the sensors at all. It is a machined piece with two studs on it. Normal US made cars you can just weld a new bung on and insert the O2 sensor.

With the 80 you have to cut that piece out, grind it clean and remove some metal to make it fit the new exhaust. Otherwise the tip of the O2 sensor is not in the exhaust stream all the way. Easy to do, but most exhaust shops just want to get you in and out as fast as possible, so it takes some time to locate a shop that will work with you. [/quote]


Christo,
I think it's time for you to go home man. Maybe you misunderstood me. But I never told anyone to remove the O2's. Just the offending cat material in between. There is no reason to have to rebuild any of the housings just cut in between them. Maybe take a little care when welding up cose to them but then again think of what temperature they operate at as well. Whatever the case step away from the Cruisers and the computer and have some...

 

[ovrroks]

I took both of mine off right after they changed the MN law. I ended up actually installing one high-flow cat and changed the muffler as the truck sounded too much like a "rice-racer"

I PM'd you with some info one where to get exhaust work done in MN.

 

[sleeoffroad]

[quote author=moralien link=board=2;threadid=6142;start=msg49683#msg49683 date=1065823627]
Christo,
I think it's time for you to go home man. Maybe you misunderstood me. But I never told anyone to remove the O2's. Just the offending cat material in between. There is no reason to have to rebuild any of the housings just cut in between them. Maybe take a little care when welding up cose to them but then again think of what temperature they operate at as well. Whatever the case step away from the Cruisers and the computer and have some...

[/quote]

Had some of those on Friday night. Actually to many of them. I was just pointing out why some shops don't want to do it. When I took the shortbus to the xhaust shop, they did a complete new exuast from the Y pipe back. We just after the flanges to the manifold and re-did everything back. Inlcuding remounting the O2 sensors with stock mounting flanges.