Improving and passing emission question.

[4x4phil]

Assuming that this is ONLY discussion, I'm curious as to what people could do to improve the emission of their cars. I've heard that people in California have ways to get their cars and 4x4's to pass that have carbs and no cats. With their strict laws how does this happen? To protect people from doing something illegal lets mark ways that have been done with "legal" or "illegal". But I'd like to hear ALL ways that this happens just to satisfy my curiousity. For example I have heard that some people remove their cats and have a peice bolted in for normal driving but put thier cats back on...Illegal. I've heard you can add things to your fuel, what can you add, in what quantities, and is that illegal? If you add something to your gas that makes the air cleaner I couldn't imagine why it would be. I've heard of people that remove a vacuum line that helps them pass. I assume that this is illegal but which one do they remove? Doesn't this usually hurt your emission results? Lets pretend that I just got a job at an emissions shop and I need to know all the ways and tricks to educate myself as a worker to protect the state and promote clean air.

 

[rockdog]

I had a 85 xj with a 2.5 that would never pass. I'd always run the tank down to about a forth full, ad a bottle of octane boost, clean or change the air filter then change the oil and go straight to the emissions place. It was only three blocks away. It would pass every time. Nothing illegal done.

 

[waynehartwig]

Just so you know, there is typically two parts to an emissions test - visual and the actual emission test. Taking the cat off, or unplugging an airline won't allow you to pass the visual and you are hoping for the guy not to notice them. Newer cars have two oxygen sensors, one before and one after the cat. If the cat isn't there, ie non functioning, it will throw a code. With any code stored in the computer it will not pass. That's one of the reasons why they are getting away from exhaust probes and completely relying on the computer to tell them if it passes or not. That is in testing phase and will be implimented in the next few years.

 

[1BadZJ]

heat

Have been told by someone that worked with emissions testing, that if you run the tank down to 1/4 or so and add a bottle or two of HEAT it will help you pass. My understanding is HEAT is alcohol based so it make you engine run cleaner. Clean air filter and oil can help also. It is all legal

 

[OCNORB]

I used to be a Davis County emmisions inspector. The best thing you can do is to get the vehicle tuned and running properly. I look at it as a cheap way to analyze my engine. When you go to get your emmisions done you want to go to a place that is not very busy, or one of those quick emmisions places. Get your rig warmed up -- I mean as warm as you can get it. Really heat that cat up. Romp on it on your way. Hot rod it a little. You get the idea. The hotter it the cleaner it will run. When I was doing emmisions I knew that some cars were borderline on passing- esp if cold. So we would drive them around a bit before testing them. The alcohol/HEAT does help. As far as I am concerned the levels that the state has set are pretty liberal. If your car cannot pass then it needs work, period. The rest of us driving around with no top on will appreciate the fresh air,too!

 

[jamesgeologist]

I have passed emmisions with my 1968 Firebird because I installed a dual exhaust system on the vehicle. The technician indicated on the display that the stock setup was a single exhaust tube and he allowed the computer to think there was still only one exhaust port. Therefore, when the sniffer was placed down the tailpipe it was reading only half the available Hydrocarbon and Carbon monoxide molecules that the engine was putting out. Thereby passing easily. Now, this modification to the exhaust is technically illegal, but there is no one that will fail a dual exhaust mod. Second, most sniffers can be programmed to multiply the readings based on the number of available ports. I cannot be sure that my Bird wouldn't have passed on it's own despite the technician's "mistake", but it sure was nice to pretend that the Bird is running clean.

 

[4x4phil]

I went through and read the post and reference post (stopped at pg 7) about acetone and it's suggested that an slight overdose of that would help also. Do you think it's possible to make a super clean gas mixture of various ingredients? What would you use?

 

[waynehartwig]

Why use Heat - It's expensive compared to a bottle of rubbing alcohol from your local drugstore!

 

[Jate]

Why use Heat - It's expensive compared to a bottle of rubbing alcohol from your local drugstore!

Can you really run rubbing isotopyl alcohol in your engine???? Are there negative effects?

 

[waynehartwig]

Nope... It's what I use all the time to get rid of water in the fuel. In the boat it happens frequently. Especially when the fuel fill is about 16" off the water....

 

[OCNORB]

Can you really run rubbing isotopyl alcohol in your engine???? Are there negative effects?

I have seen it melt the accelerator pump diaphragm out of an old carb. Best used wisely.

 

[JF1]

Just make sure you get the 99% rubbing alcohol if you try this. Most rubbing alcohols are 70% alcohol, 30% water. Rite Aid still sells the 99% stuff.

Joe

 

[waynehartwig]

Just make sure you get the 99% rubbing alcohol if you try this. Most rubbing alcohols are 70% alcohol, 30% water. Rite Aid still sells the 99% stuff.

Joe

Correct! Otherwise what point is there...

 

[waynehartwig]

I have seen it melt the accelerator pump diaphragm out of an old carb. Best used wisely.

I have dual 600 CFM Holley's on the boat with never a problem. So I guess use at your own risk

 

[anvil]

I've used denatured alcohol available in gallons at Home Depot. 4 gallons gas 1 gallon alcohol. Yes it can melt seals and hoses. It's best to dilute it after you pass.

 

[waynehartwig]

I'm only talking about a little, what 10 oz? bottle to ~15 gallons of gas...