Formula vs. Smog Check: cleaning up the combustion chambers with some B12 ( not the vitamin )

In the continuing saga of trying to get my beloved Formula to pass emissions this year I bring you my latest adventure.

Just to catch you up, the story is this.

My registration came up and when I dutifully reported to my local emissions testing station I was sadly informed that my car had failed...badly.

The only thing I passed was the gas cap test.  HC and CO were twice the acceptable values and NOx was even worse at 3 times the standard.

So I attacked the problem by switching back to Premium fuel, dealing with a bad EGR and Fuel Pressure Regulator and chasing down vacuum leaks.

Which is an excellent segue to my current project.  During my "leak" hunt I discovered that my PCV valve appeared to be the original piece.  Meaning it was time for replacement along with its associated vacuum line which after 20 years was as brittle as a potato chip.

I'd been doing some research on emissions failures and happened across a few videos about the benefits of combustion chamber cleaning.  I'm not talking about sticking a bottle in your gas tank at the next fill up.  Rather this is a process targeted specifically at cleaning up the combustion chambers and upper cylinders.  Some may call it snake oil but there is something to be said about trying to get rid of some of that built up carbon that inevitably bakes itself onto the tops of your pistons.  The cause?  Poor quality fuel, neglected maintenance and issues with the ignition system just to name a few. 

LT1's have a compression ratio of 10.5 to 1 right out of the factory, a bunch of crap on top of a piston after 100,000 miles decreases cylinder area and increases compression.  That leads to pre-ignition which is an uncontrolled explosion that happens sometime other than when the spark plug fires.  Uncontrolled explosions are ok for diesel engines, not LT1's.  It's a bad thing unless of course you like the idea of hammering the tops of your pistons and potentially bending a connecting rod.

There are a number of products out there to clean up the combustion chamber with some more snake oil than others but the two most popular are Seafoam and B12.

I chose the B12 Combustion Chamber Cleaner Part # 2610 after seeing a few YouTube videos and reading up on it.  I'd been running lower octane fuel for the past year to save a few bucks.  The car could tolerate it for awhile but not indefinitely and there would be a price to pay.

Call it a penance for the few bucks I'd saved by not giving the car the quality of fuel it really needed.

The procedure was fairly simple once I figured out what vacuum port to use.  Access to anything under the hood of a 4th generation Firebird is difficult.  Finding the right vacuum port without breaking parts that have been cooking under it for 20 years even more so.

I found a suitable port in the driver's side of the LT1 intake manifold right above the PCV valve I was fighting with earlier.  

I popped off the vacuum tee that was attached to it and connected the hose from the can of B12 making sure it wasn't in danger of contacting anything that could ruin my day.

One thing to be careful with here is to make sure to use the included hoses that come in the B12 kit.  There's an inline tee that functions to vent the line to keep the flow constant.

Once connected, it's pretty simple.  Start the car and let it run until the can is empty.  In my case it took about 15 minutes. 

I noticed some white smoke and water vapor coming out of the exhausts during the process as well as a slight chemical smell.  Nothing of note really aside from the wet spots immediately under the exhaust tips that seemed to stain the concrete a bit. 

If there was anything that alarmed me it was the sounds my catalytic converter made while the B12 made its way to the exhaust system.  A steady rattle that sounded like ball bearings in a metal coffee can.  Happily, a sound that went away once the can was emptied.

Recall that the catalytic converter is likely on its way out anyway.  In fact the whole point of this  emissions adventure is to see if I can get the car to pass without investing $250 in a new one. 

After the process completed and everything underhood was returned to normal I took the car out for a few runs up and down the freeway to burn off whatever B12 was left.  Some have reported dramatic smoking akin to all those SeaFoam videos but I didn't see much of anything. 

What I did notice was a bit smoother power delivery and a lessening of a slight miss at idle that I've had since I bought the car.  The instructions mention that using B12 may set a trouble code that can be safely reset without concern.   I saw no such code get set.  Apparently in some cases the amount of contaminants being sent out the exhaust can give a false positive to O2 sensors. 

Will this finally get me through emissions?  I don't know.  The only thing left to do now is an oil change immediately before taking it in again.  I'll wait a week to make sure all the B12 solvents are completely burned off to ensure I don't contaminate the new oil.  Not a big deal since I don't have that much oil blow-by anyway so I don't expect much of the B12 got into the crankcase.

Whatever the outcome of the test, none of these activities were a waste of time even if the car fails again.  The EGR and Fuel Pressure Regulator weren't working, the PCV valve and its grommet was overdue for replacement, vacuum lines needed to be checked, the car needed to be running the right grade of fuel and the combustion chamber was overdue for a cleaning. 

I'm just hoping I can put off the bill for a new Cat!