Just replaced O2 sensor - still get CEL - P0135...help!!

So the CEL has been on, pulled code P0135 "O2 sensor heater circuit malfunction (Bank 1 sensor 1)".

I disconnected the battery, disconnected the O2 sensor, took it out...put the new one in, connected it, reconnected battery. STILL got the SAME code - P0135.

Any ideas on what is up with it? The CEL should be off. I disconnected the battery for 10 minutes, disconnected the O2 sensor, even pulled all the plugs from the ECU. Reconnected everything and still got the CEL.

DEP ON WHAT CAR IT IS?
BANK 1 SENSOR 1 COULD ALSO BE AN A/F RATIO SENSOR

Have you tried actually clearing the code from the ECU? I would plug everything back in, erase the codes with a codereader and if the CEL comes back on, replace the O2 sensor again. Every one in a while a part is bad right out of the box. You might have a problem further up the line though too. Double check the wiring further up from the plug.

It is a 98 Accord EX, 4 door, 2.3L VTEC. I reset the ECU...shouldn't that have cleared the code? The CEL went off for about 5 seconds when I first started the car, and then it came back on.

How do I check the wiring? Just ohm it out or?

I am a mechanic at honda and we have seen a short to ground in the blk/yel alternator wire, it could cause the ecm to set that dtc and inter blow the no 6 15a fuse in the under dash fuse relay box. U need to repair the damage wire and replace the fuse if it is blown

Edited: 6/14/2007 5:28:33 PM by 92LOWYOTA

it could also set a p0141, p1298 and p0753, p1753 U also need to make sure it is a honda o2 sensor becasue i have seen aftermarket ones casue a heater problem before also

I don't know that it's really a short in a ground...how would the alternator wire cause the O2 sensor to do that?

And also, what about Denso O2 sensors? Same problem? I might go up to Honda and get an O2 sensor...but they want to charge out the ass...ALWAYS

I've been a Honda tech since 97. You have to take it somewhere that has a PGM tester,HDS, or some sort of OBD II checker and have them clear the code for you. I know that our dealership will usually do something like that for free, our service manager usually does this if asked nicely; being that it takes only a minute or two. You can't clear the code by disconnecting your battery. To be quite honest, I've never seen any short to grounds on any alternator wires causing this code. Not saying it isn't possible, just saying after almost 11 years of service work I've never personally seen it.

Here's a problem...I was trying to test the voltage and pins 1 and 2 had no reading. 3 and 4 had no reading. So I have no idea what's up with it...going to take it to the shop that did my auto to manual swap and have them jack with it.

Would a test pipe cause a P0135 code? I could try the sparkplug non-fouler trick but the code is for the O2 in the manifold. It doesn't give me any codes for cat inefficiency or low voltage or anything like that. P0135 is the only code.