I have a couple of error codes

I don't remember the codes exactly, but they are for o2 sensor heater and o2 sensor function. I replaced my o2 sensor last night, it had a steady reading of .4 volts. It now reads correctly, between .1 and .9 volts.

Now the code won't go away. I tried using my scan tool to erase them. I tried re resetting the ecu, I tried disconnecting the battery for 30 minutes. The codes never went away. They were there as soon as I turned on the ignition.

I need to figure out how to get these codes to go away. Does anyone have any suggestions?

 

If the problem is solved then drive cycles will clear them usually. You can look that up for the procedures or just drive.

 

Is the car an automatic? The TCM stores fault codes and speaks to the DME, which can still cause problems, so if you've got an automatic you need to clear all modules.

You may still be having electrical problems, have you checked the wiring harness for shorts? Did you install a quality NTK sensor or a cheap auto part store unit? We only install and sell the NTK sensors because they are the OE supplier.

Also, if you have done major work like that and can't find a fault you may want to try to clear the adaptation slots. There are 7 adaptation slots to store data on the DME, if you really want to start fresh you need to find a scan tool that will reset the adaptations and do so 7 times over to start with a blank slate.

 

I am not aware of the adaptation slots.

I borrowed a nemisys tool and when I tried to delete the codes, it said that the vehicle may need to be "key on, motor off". When I did that, the codes erased. That's what I think the problem was. I think the car may have been running when I tried to delete them before.

 

That would definitely do it, the DME can't be cleared or altered with the engine running. KOEO for near all computer diagnostic.

 

I have not done any major work. I have replaced the exhaust manifold with a header. The header was a little longer, so it stretched the stock sensor and broke it. I replaced it with a Bosch sensor.

Here's the deal though. The sensor is perfectly functional. I returned one sensor and got another one. Installed it last night. Deleted the code. This morning, I turned the key to run and turned on the nemisys tool. I was watching the sensor output as I started the car. It was working just fine, and the SES light came on within 30 seconds of running, even with a functional sensor.

 

Pretty sure you will need to drive the car more to allow the dme to adapt to the new sensor. It took a few drIve cycles for the SES light to finally go out after a rear O2 sensor replacement.

Even after the light was no longer showing it's taunting self, the code was still present as a pending code. Now, two months later, no codes present. Fingers crossed! (Till the next one).

 

Try resetting the adaptations, not sure if a Nemisys tool will do that.

If the problem doesn't go away you either still have other problems or I would recommend an NTK sensor as it is OE. A lot of the aftermarket stuff has a 53% chance of working properly when you get it from Autozone or the like.

 

I may have other problems. Last night while on a highway cruise with the nemisys hooked up and reading the O2 outpput, I noticed that instead of the normal up-down readings of a working system, the O2 output was staying on about .8 volts at all times. Only during deceleration would the voltage drop to about .03 or so. When I pulled over to the side of the highway even at idle the it was reading .8 volts.

Does anyone have a clue as to what could cause this? I am assuming because I was getting some type of reading from the O2 sensor that it was working.