I have bee reading this book lately (and highly recommend it):



From it I have learned that the oxygen sensor on our (TPI) cars produces its own voltage, which it relays back to the ecm as a measure of how accurate the air fuel ratio is at that point in time. This book also states that running a primary ignition lead close to the signal wire of the oxygen sensor can corrupt readings and even destroy the sensor. In theory I understand what is going on here, induced voltage due to the high current in the spark plug lead, but does this really happen? Has anyone experienced bad drivability, bad mileage, or even destroyed an oxygen sensor because running a spark plug lead too close to the O2 lead?

 

Never heard of that one happening. Kinda makes you wonder thou. I mean how many people have run their power wire for their sound system right by the ecm. Ive seen that done before and never seen it be a problem.

On the other hand ive seen a couple crossed wires on the secondary side of the ignition cause an inductive spark in the wrong cylinder.

 

Exactly, but this guys point is that the O2 sensor produces voltages on the order of millivolts and it wold take thousands of induced volts to fire a plug. He also claimed that this lack of tolerance for external voltage also makes measuring the resistance of an O2 sensor a no-no (only voltage readings should be made).

I didn't even think about an amps power wire. I guess that one just depends on where you go through the firewall with the it. Mine isn't even close the the ecm harness...I think...

 

Anyone???