Thread: New CAT--Would it get rid of high hydrocarbon reading?

Have failed emission test twice-Only part of test I fail is the hydrocarbons. CO and NO readings are ok. Found a vacuum leak, fixed it and that dropped the hydrocarbons about 15%, they are still too high.

Just did the plugs and wires. SEEMS to run better but I don't know. Will go test again soon.

The standard for hydrocarbons on the test is .80. My first test they read out at 2.36 and the second test at 1.96. If I can get it down to 1.59 I can get a one time waiver for two years.

My question is this: Would a brand new Catalytic Converter get me passed the Hydrocarbon test?

The cat helps burn off hydrocarbons so that may help if your car has high mileage. Double check for vacuum leaks though.

Originally Posted by OH4CompG

The cat helps burn off hydrocarbons so that may help if your car has high mileage. Double check for vacuum leaks though.

1994 3.1 has 250,000 miles on it. Mileage is around 18-19 MPG but it had dropped to 15 MPG before my latest work on it.

Originally Posted by 01GTP

See if your fuel pressure reg is leaking into the vacuum line. Also new plugs and wires will help a lot. May sound stupid but hows you air filter look?

Did plugs and wires last night. Air filter ok.

Could the O2 sensor be a problem?

Would a new CAT get me down to passable levels?

O2 sensor could throw things off. Change the oil before you take it in for test again too.