First off, this is not a Cat delete question, I want to keep the Cat in the system. I have an 85 XJ with the 2.5L and the Cat in it has the long pipes that extend up beside the engine nearly to the height of the valve covers, with the reed valves in them for air control. These take up most of the space on the passenger side of the engine compartment and I am wondering if it is possible to upgrade to a new style Cat that will get rid of that clutter? Also the rubber fitting on those pipes are getting loose and the whole side of the engine gets covered with an oil/soot mix. I need new rings for certain, but while I am doing that I was going to upgrade the Cat if it is possible.

Anyone know if a modern Cat will work without the air pump, or if there is a way to add the air pump to the older engine?

 

I would talk to a local exhaust shop.There is high flow cats on the market but not sure if they could be used on yours or not.

 

Thanks, I will ask there next week.

Louisville, cool, I am going to be up that way this weekend visiting family.

 

Do they emission test in your state? I'm in Virginia, they only do a visual. That said, I have swapped in aftermarket high flow catalytic converters in cars and had no issues. Not sure if they meet the same emission output standards as the stock setup on your 85 though.

If you are dumping oil into the exhaust, you may want to wait until after you fix the engine to install the cat. Would hate to burn out your new cat shortly after install.

 

No kentucky only test in one or two big cities the rest of the state they don't care.And the cut off here was 86 i think back when we had it so his wouldn't get tested.

 

That settles it. I would run one of these: https://www.summitracing.com/parts/wlk-15027/overview/ Basic catalytic converter with none of the weird stuff.

 

Performance-curve.com

The best source of all kinds of cats. I admire your attempts to preserve the air injection system, but it's probably more work that it is worth. A nice cat from the above site and elimination of the air pump and tubing is probably the best way to go. No longer running the air pump should also free up a few horses for you, and with an 85 2.5, you never had many to spare to begin with.

 

Actually mine doesn't have any air pump on it. It is the very old style cat where they used reed valves to let air be sucked into the cat by the exhaust pulses. That is why I was wondering if I would need to add a pump for a more modern cat. This one has two 3/4" tubes that run from the cat up beside the engine to the height of the top of the head, and you can barely get to the distributor because of them. Makes it really difficult setting the timing with hot pipes right there that you have to reach around and under. Without them I would also have room there to put a block heater feeding into the heater circuit which would help in the winter.