high HC emissions

[87GNSteve]

I went to get the smog check this morning:
RegalT...........Limit
2.35............0.8
11.18..........15.0
.062...........2.0
Car has new AC r44ts plugs, AC O2, fuel filter, fresh oil, I ran top engine cleaner a week before. Fueling or vac leaks are cause HC problems right?
What else should I check?
I dont have any scan info yet.
Car is bone stock! Inj. chip etc.
115K mi

 

[topfuel]

High HC is caused by unburned fuel.
As long as the engine is not misfiring, check for vacuum leaks or high
fuel pressure. Scan tool data would be helpful here, O2 readings, coolant
temp sensor, BL's ect...
Let us know what you're readings are, if all else looks ok the catalytic convertor may be bad too.
You may find more info in the emissions section on this site.
Good luck...

 

[ajt86]

if the cat goes bad usualy isnt the NOx high as well?

 

[85HOT-T]

Do you have a bung for an egt, or any bungs not being used. U can hook a pump to it to delute the exhaust. For some reason the epa thinks its fine even though it's the same amount of emmisions. Also drive the car for a while before you get there and try not to let it sit. The hotter you can keep the combustion chamber the better off you will be for burning all that fuel. Also do you have a colder thermostat. That will cause the computer to dump more fuel.

 

[87GNSteve]

Thanks guys, Well I discovered the crack repair on the DS header wasnt effective so I have to deal w/ that.
Coolant temps are high the previous owner must have a 195* in there.
Blms hang around 123-130
MAF range is no good @WOT its at 175-190 but at ilde is 5-6 which is OK.
O2 jumps up and down--at a cruise 500-700
I am looking to replace the injectors

 

[topfuel]

if the cat goes bad usualy isnt the NOx high as well?

NOx is usually associated with high combustion chamber temps.
The EGR system is mostly responsible for cooling the combustion temps
and reducing NOx but yes, the cat also plays a role in that too.

 

[topfuel]

Thanks guys, Well I discovered the crack repair on the DS header wasnt effective so I have to deal w/ that.
Coolant temps are high the previous owner must have a 195* in there.
Blms hang around 123-130
MAF range is no good @WOT its at 175-190 but at ilde is 5-6 which is OK.
O2 jumps up and down--at a cruise 500-700
I am looking to replace the injectors

You should see the O2's fluctuating above AND below .500 (except at WOT)
If they stay above .500 that indicates a rich exhaust. Dribbling injectors can cause that and I -believe- the leaking header can introduce oxygen into the exhaust and fool the computer into thinking the exhaust is lean causing it to dump more fuel than neccesary. There are a bunch of reasons for high HC.

Like 85HOT-T said, make sure the car is FULLY warmed up before testing.