quote:
Originally posted by Robbie Alexander:
Anyhow, besides keeping the Coolant good, the Termos good, new plugs cap and sound wires, the filter clear and good fuel (name brand) what ELSE can I do to get the most from the CAT and O2?
Also if it's not too much trouble, can you explain in a little more detail how the system works.. ie about shutting on and off (Cat or O2 or both?)
Honestly, I'd ease up on the fuel treatment. Various things can poison cats and O2 sensors, and while the fuel treatments are undoubtedly tested safe, they're tested at the manufacturers recommended dosage levels. More is not necessarily better.
As for your second question:
http://auto.howstuffworks.com/catalytic-converter.htm
Think of your catcon as an oxygen bucket. When hydrocarbons (HC: unburned gas, running rich) enter the cat, oxygen is taken from the bucket to OXIDIZE the HC breaking it down into H2O (water) and CO2. The same thing happens with CO (carbon monoxide; very poisonous), adding an O to make CO2. Performing these two transformations empty the bucket of oxygen, but normally that's not a problem because the transformation of another gas in the exhaust helps to fill the bucket by adding oxygen back.
NOx (oxides of Nitrogen) get stripped of thier O molecules (REDUCED) which are then stored in the cat, and N2 (pure nitrogen) shoots out the back of your car (along with the H2O and CO2 from above).
The computer in your truck looks at the signal from the front O2 sensor to continuously adjust the fuel injected up and down, so that you're always alternating between rich (HC in the exhaust, taking O2 from the bucket) and lean (NOx in the exhaust, adding O2 to the bucket). This action keeps the bucket from getting too full or too empty. What I was suggesting above is that maybe the too-high amounts of fuel treatment in your gas may have driven your NOx emissions so high that your O2 bucket may have gotten full and the cat would no longer able to store O2.
The computer looks at the signals from both O2 sensors; if the cat is working right and storing O2 then the rear sensor will see less O2 than the front sensor. Your code is a result of the front and rear sensors seeing close to the same amount of O2 in the exhaust. Since the computer also monitors the function of BOTH of the O2 sensors and you're not getting any codes related to them, your cat is either sleeping (I hope so!) or really dead. The only way to know is to run the highly treated fuel out, refill with normal gas (No Treatment!) get the codes reset, and see what happens. If it was me, I'd put a couple hundred miles on the truck after getting new fuel but before getting the codes reset to blow any garbage out of the cat and maybe wake her up.
hth,
Robert
