Originally Posted by taz77
that's not really much of a diagnosis, is it?
if you can get to the o2 sensor and get a voltmeter to it... do it. take a look at the numbers going back to the pcm. get a $2 bottle of propane with a on/off valve and shoot some propane into the intake. see if the voltage on the o2 increases.
if it increases really fast... like in less than a second... your o2 is fine.
if it doesn't change or changes slowly (like .2v going to .8 volts in like 5 seconds), you go a lazy or defective o2.. then replace it.
That is about 10 times harder than the HELMS method.
In the online resources thread at the top of this section there is a download for the 5th and 6th gen civic HELMS manuals. Find out what the P code is and do the troubleshooting methods listed in there. It will require a multimeter with continuity, voltage, and resistance capabilities.
hih