Hydrocarbon emissions too high need help tried everything.

[SpdElemts]

Hi guys, I’m officially stuck. I got a ticket for illegal intake and I got everything back to stock and now I can’t pass smog at the state ref. My Hydrocarbon readings is too high (15Mph: max 118 Meas 163 25mph: max 83 Meas 123) other then that i am fine. Got a brand new cat and no change at all. Went back with brand new cap/rotor, spark plugs and wires, air filter, and some acetone in the gas tank and no change it actually got higher. I need help guys. Is there any way to lower my hydrocarbons at all? Or some way to make my car run really lean just to get it tested. I’ve made 4 trips to the state ref already and i am getting tired of this. So any help would be much appreciated.
BTW a friend suggested that I disconnect the vacuum hose to the Fuel Pressure Regulator and plug the hose up then go test my car. I doubt this but if anyone could explain to me why this might help then I might just go get it tested with the FPR disconnected from the vacuum hose.

Thanks, Jeff

[EchoOfSilence]

how bout a new cat.

[cdlong]

how bout a new cat.

good job reading

Got a brand new cat and no change at all.

not that a cat would help for hydrocarbons anyway, it takes care of NOx.
try some injector cleaner or one of those fuel system flushes. check your timing.

[ledzeppelin240]

The HC emissions are controlled by the EVAP system, PCV Valve, Air Pump(Air Induction Valve) and believe it or not the Catalytic Converter. The ignition system is what usually causes high HC levels, because there is excessive unburnt fuel.

Air filter, fuel filter, condition of the fuel system, spark plugs, spark plug wires, distributor cap and rotor, and regular oil changes also contribute to your emission levels.

Some tips that I found in a book I have are:

1. Test your vehicle on a nice day. Cold weather requires that the engine run longer for the engine to reach operating temp.

2.Battery must be in good condition. A weak battery causes fuel-injected engines to run too rich.

3.Change engine oil before having the vehicle tested. Dirty or contaminated oil increases exhaust emissions.

4.When fueliing your vehicle, do not overfill the gas tank, cause then liquid gasoline can be drawn into the engine throught the canister purge system.

5.Using premium-grade gasoline helps prevent NOx emissions.

6.Drive 20 minutes before the vehicle is tested to ensure that the engine oil, coolant, and catalytic converter are at normal operating temp.

7.While waiting for the inspection run engine at a fast idle. (Hmm..???)

8.Make sure your A/C, heater, and defrost is all off preventing extra load on the engine.

[SpdElemts]

Anyone know anything about the unplugged vacuum hose off the Fuel Pressure Regulator?

[steve shadows]

The HC emissions are controlled by the EVAP system, PCV Valve, Air Pump(Air Induction Valve) and believe it or not the Catalytic Converter. The ignition system is what usually causes high HC levels, because there is excessive unburnt fuel.

Air filter, fuel filter, condition of the fuel system, spark plugs, spark plug wires, distributor cap and rotor, and regular oil changes also contribute to your emission levels.

Some tips that I found in a book I have are:

1. Test your vehicle on a nice day. Cold weather requires that the engine run longer for the engine to reach operating temp.

2.Battery must be in good condition. A weak battery causes fuel-injected engines to run too rich.

3.Change engine oil before having the vehicle tested. Dirty or contaminated oil increases exhaust emissions.

4.When fueliing your vehicle, do not overfill the gas tank, cause then liquid gasoline can be drawn into the engine throught the canister purge system.

5.Using premium-grade gasoline helps prevent NOx emissions.

6.Drive 20 minutes before the vehicle is tested to ensure that the engine oil, coolant, and catalytic converter are at normal operating temp.

7.While waiting for the inspection run engine at a fast idle. (Hmm..???)

8.Make sure your A/C, heater, and defrost is all off preventing extra load on the engine.



DITTO, timing is everything. My KA is running extremely rich right now due to some old bad fuel injectors. Is this a single cam with top feeds by chance?

[TibDrifter]

use about 10% alchole(rubbing alchole) and drive the shit out of it before your test, get it hot. take your spare tire off, jack and put the minum amount of gas in your car. drive real hard before your smog test....you will pass

[SpdElemts]

Does anyone know what would happen if i unplugged my vacuum hose to the Fuel Pressure Regulator?

[94_240sx]

I have base model 95 MX-3 which is a daily driver and had exact same problem last week. At 15mph, 141 is max in Texas. I had 199. Did full tune up since it was due anyway. New plugs, wires, rotor, cap, timing belt, water pump, trans mount, engine mounts. intake tube(cracked), oil change whole nine yard. It went down to 152. Still couldn't pass. My car was running slightly rich. So adjusted the timing and we heard knocking noise, so put it back the way it was. Finally, installed new cat and guess what? I got 11. In your case, adjust the timing. I think it'll fix it. BTW, intake cleaning with Seafoam should help too. I'm not sure if this is true or not, but someone said adding alcohol or water will clean up O2 sensor and decrease HC reading little bit... People say MX-3 O2 sensor should last forever, so I didn't bother to replace it.

[ManoNegra]

O2 sensor can easily go bad. Running rich can destroy them as well as a small amount coolant in the gas. 02 sensors, like anything, don't last forever.

[94_240sx]

O2 sensor can easily go bad. Running rich can destroy them as well as a small amount coolant in the gas. 02 sensors, like anything, don't last forever.

I know. I replaced O2 sensor on my S13, but went to Mazda dealership and everyone said they never sold MX-3 O2 sensor to anyone, and not to worry about it. It was odd...

[Kwick Silver SF]

Drop everything and buy a bottle of Blue Sky!! check some of my old posts, or check out this website http://www.blueskycleanair.com/ we sell this here at my shop, so stop by and check it out, its only $20.00 and if you dont pass, we will give you your money back with proof of Failing emissions!

[SpdElemts]

would anyone know if i can lower my hydrocarbons if i set up an SAFC to make my engine run leaner?

[ledzeppelin240]

Excessive hydrocarbons means unburnt fuel, not that your engine is necessarily running too rich , just that the fuel is not being ignited which could mean ignition system problems.

You obviously have a engine problem and by attempting to cover it up is not really helping. As long as a engine has had regular maitenance done and no matter what the milage...to a point, it should be able to pass emmisions.