Thread: what can i do to fix my hydrocarbons problem

i was tryin to run my car through inspection and my car failed due to high hc what would cause this and also my hose running to my A.I.V id busted but it doesnt have anything on the otherside. it came like this from the guy i bought it off of. theres alot of work that need to be done

Possibly the catalytic converter? How does the air filter look?

also where did it fail? at idle?

oops! double post!

it just said it failed i ran a 275 instead of 220 thats all i know. im wondering if bad gas has anything to do with it it was sitting for a bit since april atleast and for some reason when idling it bogs slightly not much but its noticable. it failed when they told me to accelerate and hold. now my research has told me that it could be a number of things from vacuums to spark plugs to the wires and anything that creates spark. what is a sure fire way to find out cause im a little tight on money and need to get this car passing so i can have a normal work schedule again. lol

hook up everything how its suppose to be, get that crappy old gas out, put some
good gas in, not no arco crap.. do a full tune up, plugs, wires, cap an rotor, prolly wouldnt hurt to change the oil just because.. also before your next test drive the piss out of the car, get the cat warmed up real good.. an make sure your timing is around 10-12*

i would start with this 1st.


found this on the internet just to give you an idea of why you have high HC



. WHAT CAUSES HIGH HYDROCARBON (HC)?
Below are common failures which are likely to produce high Hydrocarbon HC. Hydrocarbons are basically raw fuel, otherwise known as Gasoline. High Hydrocarbon (HC) emissions are almost always a sign of poor fuel ignition. However, it's not always that the engine's ignition system is responsible for high Hydrocarbon emissions. Read on.


1. Improper Ignition Timing - Engine ignition timing is measured in degrees before or after Top Dead Center (TDC). Example of an ignition timing failure would be in the case where an engine's ignition timing is required to be set at 10 degrees Before Top Dead Center (BTDC) and instead is set to 15 degrees BTDC. This fault will not only cause a smog check "functional failure", but will increase Hyrdocarbon (HC) emissions as well. California allows 3 degrees +/- off of the manufacturer's required setting. Note: Late model vehicle's may not have a distributor, and therefore no timing adjustment will be needed. On these engines timing is electronically controlled by the ECU (Engine Control Unit).

2. Defective Ignition Components Your vehicle's ignition system consists of the ignition coil/s, distributor*, distributor cap*, distributor rotor*, ignition wires, and spark plugs. If any of these components are defective the engine will produce high hydrocarbons. A common reason ignition components perform poorly is due to carbon build-up. High ignition voltage traveling through the air pockets within these components form carbon. Carbon acts as an insulator between paths of electricity, decreasing the energy required at the spark plug to ignite the air/fuel in the combustion chambers properly. *Distributor-less engines do not have these components.

3. Lean Fuel Mixture - Any condition which will cause unmetered air to enter the intake manifold, and ultimately the combustion chambers, will cause high hydrocarbons (HC). This condition is called a lean miss-fire. Such faults as vacuum leaks and gasket leaks will cause lean fuel/air mixtures. Broken, disconnected or misrouted vacuum hoses will do the same. It is also important to note that many engine components rely on engine vacuum for proper operation. If any of these components are defective, externally or internally, they may cause large vacuum leaks as well. A good example of such a component is your vehicle's power brake booster.


4. Defective Catalytic Converter - A defective catalytic converter (CAT) may be responsible for high HC, CO, and NOx emissions. The Catalytic Converter, commonly referred to as the CAT is a component designed to continue the combustion process within itself and emit a more thoroughly burned and less harmful emissions containing exhaust. The most accurate way to find out if your vehicle's CAT is working efficiently is by using an exhaust gas analyzer. Unfortunately this tool is fairly expensive. Testing the CAT should be conducted at a smog check repair station.

Some obvious symptoms of a bad CAT could be any of the following:

a. Major loss of power over 15-25 mph. This may be an indication that the catalytic converter is plugged up and restricting exhaust flow.

b. Strong sulfer or rotten egg smell emitting from the exhaust on an otherwise good running vehicle. This may be an indication that the Catalytic Converter isn't burning fuel completely, instead storing it, then releasing it as hydrogen sulfide.

c. Loud rattle being heard from inside the CAT. This may indicate a broken Catalytic Converter substrate. You may want to insure this sound is not due to loose exhaust components, i.e. broken muffler flanges, loose exhaust pipes, loose or cracked exhaust manifold.

5. Defective Air Injection Components - Faulty smog pump and related emissions system components will cause high HC. The air injection system is designed to introduce additional oxygen, after the metering system, to the engine exhaust as it exits the exhaust manifold, or directly before it enters the Catalytic Converter; thus burning whatever remaining fuel (HC) in the exhaust completely.


6. Low Cylinder Compression - This fault is one of the less common high HC causing problems we encounter. Reasons an engine may have low or no compression in one or more of its cylinders may include things such as burned intake or exhaust valve/s, defective valve guides and/or seals, defective piston rings, and burned head gasket/s. A wet/dry cylinder compression test will diagnose this fault. More then often if such a problem exists it will be very apparent. You should notice rough idle.

im leaning toward the electrical or vacuum cause in delawares test it shows what passed and what doesnt as far as emissions and it says the cats ok and everything i also want to know what the aiv does because thats where the line is broken.

It just says the CAT is ok if you HAVE one. I ran my VE thru in CT and failed, my HCs were high. I replaced the CAT with a universal replacement one, and EVERYTHING, my NOx, my HCs, etc, all dropped considerably and I passed. You can get a cat online for a bit over $100 and call it a day.

it says pass on the cat

Do NOT decrease timing. INCREASING timing leans the mixture out. This allows for a better fuel burn.

Also, drive the car around for a good 20 minutes, with good amounts of load. I drove my old Del Sol to the emissions station 15 minutes away, and never went into 5th gear at highway speeds. The hotter the cat, the better.