Here in British Columbia, Canada we have a little government program called Air Care (sounds pretty similar to the emission controls alot of you Americans have to deal with).

Anyways, I ran my 93 LT1 Formula through emissions right after an oil change and a fill up of 92 Octane. Everything passed great, except for my Hydrocarbons. The passing level is .500, mine ran around .926 or something. I took it to my mechanic who suggested Wynn's Emission Control (an additive you pour into your fuel tank). I went through Air Care with about a half tank and the additive, and lowered my hydrocarbons to about .614. Quite an improvement, but I still failed.

I was just wondering if anyone knows the most common reasons for high level of hydrocarbons in your exhaust? A bad catalytic converter, O2 sensor...? The car has 170,000 kilometres on it (NOT miles) and runs really well.

Any thoughts?

 

This is what I would do, since I have ball breakin emissions.

CHnage the o2's, plugs, wires, oil change, PCV, and possibly a NEW cat. The put highest octane in the car and add a bottle of rubbing alcohol. 180 temp thermo and make sure the car is nice and hot before you put it on the machine.

Ive passed every time!

 

If its the original cat, its shot.

 

I'm pretty sure it still is the original. I put in a cat-back exhaust not too long ago, but I guess it's due for a new converter.

Is it really worth getting a high-flow? Aren't they like 250-300?

 

I would also say you are do for a cat. Here is a great article on cats
that was originally posted by stereomandan:

http://www.installuniversity.com/ins...n11.122001.htm

 

Unburned HC's can come from a leaking injector. If it was running too rich, you would be high on both HC's and CO...... how does your CO look?

 

I dont mean to bring this up or anything, but would all of the previously mentioned information still pertain to my car?

Low RPM hydro carbon reading: 1099
Limit: 220

High RPM Carbon Monoxide Reading: 1.51
Limit: 1.20

I have a gutted cat thanks to the previous owner, but i was wondering if anything else mentioned above would help me out. As well as helping my idle out too?