I scanned the groups looking for a suitable place to post and wound up here looking for information about an O2 sensor tester I aquired. A friend of mine gave me a tester that has the key strings "Cat Master O2 Tester" and "Walker CleanAir specialists" on the front. I expect to use it in my ECM hacking and other related projects so I'd like to find out how to use this thing. The concept of operation is understood, and I'm just having trouble figuring out how to connect it to the sensor circuit. It may not only test sensors but simulate them to the ECM as well...I don't know.

I've searched high and low on the net for a hit on these keyword strings and have come up empty handed. The thing has a black ground lead as well as a red and a yellow hook probes. I'm looking for a user's manual or someone to tell me which lead is which on this thing. Any help is appreciated.

-dnult

 

It doesn't have enough leads to do a proper O2 feedback, for serious hacking.

The ecm looks for a feedback based on time.

The easy way to cheat and get a workable O2 feedback is using the distributor reference pulse to trigger a feed back voltage that toggles across the O2 ref voltage. Might need to add a 555 in the toggling depending on how accurate you want the O2 feed back to be. It's a real PITB to get all this right.
HTH