cat convertor

[atv087]

ok my cataltyic convertor rattles like hell all the time and i havea feeling its restricting my exhaust how hard is it to change and what size cat do i need to replace it.. i have a 92 eighty eight royalle

[RRS]

If your state has no smog test. Just have a local muffler shop cut it off and put in a straight pipe in its place, I told my shop I wanted a "test pipe" installed.

If you have to buy a cat I would look on ebay for them I found when I was looking for around 30-60 bucks. Magnaflow high flow cat, the pipe should be 2.5"

With you car I would cut it off and to contary to what some people say Mine runs a hell of alot better since it got cut off, now my check engine light stays off. The reason you can cut it off is because unlike new cars there is only one o2 sensor on your car located on the exhaust header. If you had 2 then you would have to buy an o2 simulator.

Anyways cut it off aor buy a high flow one its your choice.

Don

[atv087]

we have emissions testing here in new york so chances are it would not work if i have them put in a test pipe

[Hansnet]

Originally Posted by atv087

we have emissions testing here in new york so chances are it would not work if i have them put in a test pipe

It is actually aganist federal law to remove it and there is a large fine associated with having it removed.......in any state



High flow cat from magnaflow 2.25" ebay = $40 or $50 + installation.

[atv087]

you sure its 2.25 for a high flow cat i read in a few other places its 2.5 but i dont want to get the wrong one

[tri-power]

ATV, I live in New York and know about the emissions law. If you have a Cole Muffler near you, take it to them and they can test to see if you have an exhaust restriction. I'm willing to bet that the rattling you hear is the heat shield. They are common here to break loose at the spot welds. They have no affect on the performance of the cat. , rather they are designed to keep heat away from the car. They are not going to cause the car to fail emissions, but create a nuisance while driving. If you decide you need to replace the cat. , the easiest thing to do is look for a direct fit cat. This will minimize the amount of work you have to do to install. As far as the emissions tube goes, a direct fit cat will have the appropriate setup, although I know that our 1991 doesn't use the emissions tube. Try going to walker exhaust website and download a diagram of your cars exhaust so you know what you need to get, even if you decide to buy another product. If you decide to get walker, they sell it at Advance Auto Parts.

[atv087]

no cole muffler neer me i live down in westchester. Also the hunneycomb thats inside the cat is whats broken apart and supposidly affecting gasmilage accordign to the shop

[tri-power]

That sounds right, when the honeycomb breaks apart it will collect and restrict airflow. So when you accellerate and build up exhaust pressure, the gas has nowhere to escape causing the car to bog down. Also because you live in Weschester county, I believe you also have to pass NYC emissions not just NY state emissions, which means not only do you need to have the cat on but it has to be functional. So the "test pipe" and hollowing out the cat are not options you can take. I'd also consult a muffler shop about using a performance cat to see if it will change you exhaust gas values.