HC- 2000 limit-114
CO- 1.58 limit- .68
NO- 1824 limit- 796
Car is bone stock, 155k miles. Has a fresh 02 sensor, the other was changed 4 yrs ago. I've put 35k miles on it. EGR is plugged. Gas mileage is fine but I fail the sniffer test. Do I need a new cat?

 

Wow... when was the oil changed last? Do you have any fuel additives? Car is emitting a LOT of hyrdos.... there is definately something wrong. How is the car running?

 

It runs fine. Its probly time for an oil change. Does that really effect emissions? Theres no fuel additives. I'm running regular(87) gas too.

 

Change the oil for sure. That definately has an affect on the emissions. Possible you have bad rings or valve seals. Any oil while running or at start up? 87 octane is a bad idea. These cars were designed to run on 91 and above. Put some good gas in there and change the oil. Check your spark plugs for build up. Do an all around check of the tune of the car.

 

a cat will fail in 1 of 2 ways...

#1 the cat gets clogged and will choke the exhaust system resulting in poor performance and may eventually lead to...

#2 the cat's internal "honey comb" structure fails and is expelled through the exhaust tip this of course makes the cat useless. If you notice things that look like a wasp nest coming out of the exhaust then you either parked too long or the cat failed.

If your car runs fine you probably need a new catalytic converter

 

Cat can also "fail" because the catalyst is contaminated. It looks like you're putting out raw exhaust that hasn't been cleaned by the cat at all. If it was simply running rich, the NOx would be low. But since HC, CO and NOx are all sky high, its pointing to the cat. HC's don't have to come from the oil.... they can come from unburned fuel in an engine running rich, leaking injectors, or from a cat that is not oxidizing them to CO2 and H2O.

 

The guy told me the highest he can read on the hc is 2000, so its actually over 2000. Is magnaflow a good cat?

 

Your all around bad.. so looks like your cat is toast. But with HC that high i would imagine somethign else may be happening too. If you fail a 2nd time after a new cat you probably have a fuel vapor leak...