Went looking around underneath today.

Noticed no converter. sensors are in place and looks like a tube was welded on in place of the CC.

1. If I put in a cc what are some of the problems I may encounter. She runs fine now, I get about 350- 385 on a full tank.

2nd sensor



1st sensor with the header right behind it



oh and what rear end do I have d35 right?

 

Looks like you have the D35 rear, yes.

As for problems after a cat installation, I don't know why you would have any. It should eliminate the CEL/codes you're probably getting now (and if you're not getting any codes, I would check to make sure the bulb is still hooked up in the cluster..)
I put a Magnaflow cat on mine, works great as far as I can tell, direct fit, and about 115 shipped off of ebay.

 

You are correct sir you have a D35

 

Please refer to this thread about CC...Tj
https://www.cherokeeforum.com/f2/cat...er-laws-24337/

 

how on earth is that setup not throwing any codes? x2 on checking the bulb.

you're jeep is 100% illegal right now. Get a new cat in asap. x2 on the magnafow cats

 

No codes? Still passes IM? Why put one in? IDK just thinking out loud.

 

because it's the law and on this site we always promote legal modding and wheeling. Try reading the rules before thinking out loud

 

ok, it does throw a code,

P0420 low efficiency, erases for 2 days and comes back.

It will be fixed looking into right now.

any suggestions on a good high flow cc, and muffler. I'm just going to do from the header back. Thanks.

 

I forgot who.. But check out the vendor section. They have some good stuff.

 

Btw as far as mpg. Here's my experience.. One day my cat fell off. Went to the shop to weld it back on and it was to far rusted to put it back on.
So I stuck a straight pipe on just to quiet it down and to get to pay day so I could purchase a new cat. This was only a Temporay fix to get by.
Durring those 4 days I noticed my mpg got worse.
Friday purchaced a new one put it on and it's been better since then.

 

For the time being, our downstream O2 is plugged into the factory harness but just wire tied to the ebrake cable.....no CEL, codes or issues.

 

Catalytic converters are “sized” according to the number of cells per square inch. (A cell is one of the tubes of the catalyst brick that the exhaust gas flows through.)

Most OBD-II vehicles have 400 to 600 cells per square inch. Fewer cells per square inch flows better but doesn’t process the exhaust gas as thoroughly. So there is a chance that you can install a new catalyst and still have a code P0420.

Random Technology offers two direct-fit applications for your Jeep, P/N 192-22003 or 192-25001 (depends on build date). This is the catalytic I would go with, for reasons of the balance they achieve between emissions control and exhaust gas flow. This is a $225 to $250 part… which sorta makes it a pain in the butt to voluntarily keep your vehicle compliant, doesn’t it??

 

Ok guys, after reading all of this I am about to order a new cat (the old one got crushed by a rock, and I couldnt afford a new one so the muffler guy stuck a straight pipe on it) I drive a 1991 XJ and I was wondering if anyone could tell me if there are o2 sensors before the cat, I'm not sure what all the muffler guy did, I dropped the car off, told him to fix it for the least amount of money and I got a straight pipe.

Any help, or pictures will be greatly appreciated. I am thinking about getting a Flowmonster Cat (look at it here) any sugestions?

I dont want to break the law, esp, when I am as noticeable as I am right now.

 

Also, did I mention I get HORRIBLE gas mileage? 12MPG on a good day... going downhill... in neutral...

 

I believe '91s (OBD-I) only have one O2.....located beside the motor, drivers side. When was your last tune-up?