y7wu

Hi, I just had my emission inspection,

my HC ppm at 40km/hr is at 53 (55 is the limit)
at idle its 21 (200 is the limit)

2 years ago it was 6 and 7 respectively.

what could be causing this? I passed emission but I dont want to fail the next one or have bad gas mileage.

Any ideas?

Thanks in advance

TLin401

Tune up?

tmnhs81

What were the numbers for NOx, CO, CO2 and O2?? Maybe I can help. Just from the HC it sounds like misfire..

Go90go

Just change your plugs and clean your EGR and you'll be fine. That's what gets the HCs down.

~Cheers~

desired_speeds

not necessarily. It could be much more than that.

tmnhs81

I am sure EGR have very little to do with high HC.

To OP, hows car running? Any rough idle or driving condition??

Go90go

^ Worked for me.

~Cheers~

tmnhs81

^You are weird...

y7wu

Here are the numbers

=== CURB IDLE ===
HC ppm: 21 (limit 200)
CO%: 0 (limit 1)
NO ppm: N/A
RPM: 640
Dilution 14.60

=== 40 km/h ===
HC ppm: 53 (limit 55)
CO%: 0.06 (limit 0.31)
NO ppm: 46 (limit 0408)
RPM: 1623
Dilution 14.66

The car otherwise is running fine. No rough idle. The only thing I notice is sometimes a rougher shift from gear 1-2 (or 2-3?). I did a drain and fill of my transmission fluid with OEM honda fluid but didn't notice significant improvement..

What are symptoms of misfiring?

Thanks.

TLin401

When you did the drain and fill, did you replace the tranny screen/filter?

TexasHonda

Carefully inspect PCV valve and hoses (intake and delivery). A blocked PCV or PCV hose can force excess oil into the engine through the PCV air intake (reverse flow). This would also cause excess HC.

good luck