I recently did battle with a P0420 code. The PCM samples the pre catalyst oxygen sensors and compares those readings to the post catalyst oxygen sensor to determine if the catalytic converter is doing its job properly. I could not get a hard explanation on what exactly the PCM looks for when comparing the pre and post oxygen sensor readings and the exact parameters for setting the code. I watched my post sensor with a graphing scanner while driving in all types of conditions. It was usually a steady line with a few slants up or down, when slowing to a stop after highway operation it would cross from rich to lean a few times (cross counts). After my experiment I think the PCM looks for a steady reading from the post oxygen sensor. There is probably some kind of threshold as to the number of times for the post sensor to cross from rich to lean.
One thing that really helped to diagnose this trouble was to use an oxygen sensor simulator such as this one: http://www.bigdaddiesgarage.com/straight-cel-fix.html
This device moves the sensor further away from the exhaust stream and makes it less sensitive. A real handy device to tell whether the converter is actually inefficient or the problem is elsewhere. So far my test has shown that the converter is just on the ragged edge of being inefficient and the code has not reset with the simulator installed.
That "simulator" can also be found at your local parts store HELP section but, is known as a "spark plug non-fouler"
Part # 42002 would probably work for the S-10. It's used in a lot of different rigs to get rid of a MIL. I have a couple that I need to install on the 2 mini cats in my heep until I can afford a replacement from Rock Auto.
[size=75][b]"For those who have fought for it, [i][color=red]FR[/color][color=white]EE[/color][color=blue]DOM[/color][/i] has a taste that the protected will never know."
[url=http://www.naxja.org/forum/showthread.php?t=73349]GUIDE TO SEARCHING. [i] (Some of the forum software is different but, it has helped me a lot.)[/i][/url][/b]
[b]"Those who don't know history are destined to repeat it." Edmund Burke[/b][/size]
The non foulers will work and save about 10 dollars. There is a little extra labor involved to drill out one of the non foulers for the sensor tip to clear.
hootz wrote:The non foulers will work and save about 10 dollars. There is a little extra labor involved to drill out one of the non foulers for the sensor tip to clear.
That's right and I meant to mention that but, forgot. I don't recall the drill bit size but, I had one and with a vise it took under a minute. A yr ago before the garage, vise and workbench it would have been an ordeal using a visegrip, standing on it and trying to drill it out.
[size=75][b]"For those who have fought for it, [i][color=red]FR[/color][color=white]EE[/color][color=blue]DOM[/color][/i] has a taste that the protected will never know."
[url=http://www.naxja.org/forum/showthread.php?t=73349]GUIDE TO SEARCHING. [i] (Some of the forum software is different but, it has helped me a lot.)[/i][/url][/b]
[b]"Those who don't know history are destined to repeat it." Edmund Burke[/b][/size]
roadrunner wrote:Given your duck problems Reed...................
Shhhhhhhh, dammit. They haven't figured out that I am still wrenching, just outa sight.
[size=75][b]"For those who have fought for it, [i][color=red]FR[/color][color=white]EE[/color][color=blue]DOM[/color][/i] has a taste that the protected will never know."
[url=http://www.naxja.org/forum/showthread.php?t=73349]GUIDE TO SEARCHING. [i] (Some of the forum software is different but, it has helped me a lot.)[/i][/url][/b]
[b]"Those who don't know history are destined to repeat it." Edmund Burke[/b][/size]
