Mohammed

What is the average(acceptable) reading of the HC ?


Came from emission inspection and car failed due to High hc !!

what cause high HC ?

what to check first ?


mods : cam,boltons, no cats , no egr

Stroked96Bowtie

iTrader: (22)

With no cats, could be causing it. I know once I took the cats off my LT car, was tough passing inspection after that. Some advice I was given, take the car for about a 30mi ride just before attempting inspection, include highway driving.

All else fails, need to find a 'friendly' inspection house. What I ended up having to do.

*Edit: Did a quick google search, this should help:
http://www.smogtips.com/failed-high-hydrocarbons-HC.cfm

Mohammed

I passed emissions after few runs at wot and ac on. If high hc is a fuel problem I need to findout the reason for that !!

Saw the link ,


Does anyone have an idea where to start ? what to check first

VAformula

iTrader: (8)

"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."

By defective they mean your lack there of, unless for some reason you're running lean, you probably need to put the cat back on, or find a inspector that doesn't care about emissions.

Ed Wright

iTrader: (1)

Doesn't have to be fuel. Advanced timing will raise HCs too. Why do you think factory calibrations have the timing backed up so much al low RPM?

VAformula

iTrader: (8)

Very true, never thought of that.

Mohammed

Then I need to check air/fuel ratio first.I don't think the stock exhaust will be available !! C4s are rare here !! and btw , it passed the emission in the second try lol. Doesn't mean the car was fine , it means the emission laws here are .




let me that !!

VAformula

iTrader: (8)

Yeah, here in Virginia my tuner is an inspector, go figure (so he puts on stock tune to pass emissions then puts it back. That's for ya)

Ed Wright

iTrader: (1)

You can google what you want, but I had my own exhaust 4 gas & 5 gas exhaust analyzers for over 30 years, I can tell you that is the case. If you are going to tune modified vehicles to pass emissions you have to know these things. Endless testing is part of the job. Driving cars, loaded at part throttle will open your eyes you won't learn on the Internet. Sometimes you just have to step into the real world. LOL

Mohammed

thats great, but I'm not good with tuning. and I needed to know what you mean by Advanced timing.

Ed Wright

iTrader: (1)

Spark advance is also called timing. Advanced timing is more spark advance. 40 degrees timing is more spark advance, or more advanced, than 30 degrees.
You are tuning a car?

Mohammed

No , I just want to fix the High hc problem. Strong smell at startup , which is also dangerous for health.