Ok well here is the situation I am in. I have a 2000 GSR with 60k miles. I rebuilt the motor in February and when taking off the stock header the exhaust dropped and pulled the secondary o2 sensor wires out of the clip. The wires pulled out on the wire harness side of the sensor. Anyways I just rewired the secondary o2 sensor today. I had to hard wire it since I lost part of the clip and couldn't find a diagram anywhere. Everything worked great I let the car idel, no CEL or anything. So I took the car out drove about 10miles came home still no CEL. Went out drove about 30miles then the CEL comes on. I checked the code right away and it ended up being CEL 67 (Catalyst low efficiency).

Anyways is it possible that the cat could have clogged already with only 60k miles? Or is it possible it has something to do with the secondary o2 sensor that I just wired? The secondary o2 sensor has not been used for months so could it have clogged just sitting in the exhaust?

Mike.

 

Any Ideas?

 

???

 

P0420 is 3 trip logic, ECU must see low efficiency 3 times in a row before it triggers the CEL. I'm guessing it has something to do with your secondary O2 sensor. Did you solder the connection or just crimp? Soldering would be best. Try rewiring first since the OEM O2 sensor is quite pricy.

 

I didn't solder my secondary. It was pretty hard to get a solder gun down there. Anyways if the connection wasn't good enough wouldn't it throw a code 63 or 65?

63 Secondary oxygen sensor
65 Secondary oxygen sensor heater

 

65 is the heater circuit, so that's kinda different anyway.

It won't throw 63 unless the connection you made is so bad that the ECU sees over-range or under-range. More likely, the signal is in range, but it's incorrect.

 

When me secondary o2 wasn't wired I was throwing a code 65. I wired it and the code cleared. I'm confident that the sensor is wired correctly. I'm kind of confused of what you mean by the signal is in range, but it's incorrect?

 

The heater circuit is pretty simple. Either it works or not. The sensor signal is like 0.1 to 0.9 volts, and I think it has to go outside that range before the ECU recognizes it as a bad sensor.

But if your crimped connections has any little corrosion or dirt in it, or it isn't quite tight enough, it might influence the signal a small amount. The ECU 'thinks' that the sensor is OK so it must be a bad cat. Just try soldering the signal wires & reset your ECU. See if the CEL comes back...

 

Alright i'll try that.