I'm sorry for the looong story leading up to this, just scroll past the break to get to the main point and skip the drama...

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I bought my Max- 96 SE w/ S&C Package from a college girl a in Feb.- check engine light was on (yeah yeah, I know I bought a car w/ CEL on, but I trusted her ) She says that she had just had a diagnostic done and it was because the O2 sensor had just gone out, so I had her bring down the price on the car to $4500 from $5000 and figured I could just replace the thing easily...

Well, I hadn't found the .org yet, and had no clue that you could pull codes on a Max yourself. So I paid $30 to have a diagnostic run on it (AutoZone here dosen't do it free anymore) to see which sensor is bad and it gives me these codes...

P0135- O2 Heater CKT Bank #1 Sensor #1
P0325- Knock Sensor #1 Malfunction

A bad knock sensor too? - Well, I later found out that the KS code can show up as a ghost code, but w/ the mileage (158,000) I figured I'd replace that too and it turned out to be cracked.

As for the O2 sensor, I was now looking to see where Bank 1 Sensor 1 was located and found a site which apperently does not apply to Maximas (can't find the URL now) that said Bank 1 Sensor 1 was the front Left Sensor.

So I toodle down to AutoZone and bought their last Front Left O2 sensor - BOSH OEM replacement part ($84), and ordered the KS from NAPA ($180).

In the mean time I find Maxima.org and these forums and find out you can reset the ECU and pull codes yourself.

After I got the parts, and spend a whole day at my mechanic's house changing the KS and O2 sensors, also cleaned the fuel injectors and changed the oil- We reset the CEL and I go on my marry little way...
Well, On the way home the CEL pops back on! I get home and pull the codes and get:

09 01 - front right htd O2 sensor heater

OMG- Now I find out that it is the front RIGHT that's out, not the LEFT that we just changed!- So I call all over town and no place has this part in stock and only NAPA will special order it for me- I get them to match AutoZone's price and order the Bosh OEM Replacement O2 Sensor.
When I go to pick up my part today, they hand me a NAPA Brand O2 sensor, which looked way different from the Bosh that was in the car, the guy there tells me "well it will work better than a Bosh, it's what Nascar uses"- I just say whatever and head over to have the thing changed.

Well, we go through all this and get the Front Right O2 changed and reset the ECU. The light was off on the first start, but on the second start it came back on.. pull the codes and get 09 01 again!!!
Reset it again and on the SECOND start again it pops back on the CEL. It keeps poppong up the CEL on the Second start w/ the same code.

We have checked the connections and I really do not think that the new O2 sensor has an out heater! The only thing that we can come up with is that there may be a problem w/ the ECU not even sending the signal to the heater to turn on, and then saying that it is not working- does that make sense? Could it have somethig to do with the NAPA brand sensor (doubt it)? I'm all out of Ideas and energy at this point.

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To get to the point for those who did not want to read the long story above...

I got code 09 01 for the front right O2 sensor heater, replaced the whole thing and I'm still getting the code on each SECOND start after resetting the ECU. Would this then be a problem with the ECU itself since there should be no problem with the New O2 sensor? Is there a different way I should try resseting the ECU- (disconnecting the battery or something?)

Please give me any advise or opinions you have, Thanks so much for your time and help!

 

I would never ever use any 02 sensors but the ones from nissan. It doesn't even matter if its the same brand as the stock brand. I would not buy an 02 sensor from anywhere but the dealership

 

Hmmm, maybe this could be part of the problem then *crosses fingers*

I'm gonna have to have it out w/ NAPA for giving me the wrong part, the Bosh/ OEM that I got from autozone seems to be working fine for the front left (not that I can really tell) But it looked exactly the same as the original one from the car which was Bosh/ OEM. I chose to get it from AutoZone because it was the same part and the dealership quoted me @ $160.00!!

 

yeah dealership likes to mark stuff up bigtime. however on sensors and critcal engine parts sometimes its ok to bite the bullet. Its kinda like people try to buy other spark plugs than NGK but then learn the hard way that maxima's only like NGK

 

There are some items that you really should always replace with OEM equipment.

 

Well,
Today I took out the Napa o2 and replaced it w/ the original sensor from the front Left (it should still be good, since the wrong one was changed the first time around) reset the CEL and crossed my fingers... on the second start CEL again w/ the 9-1 code. Tried unplugging the battery thinking that may reset it all the way. Nope, CEL on the second start.

I guess the only way to fully rule out that it is ths sensor making the code is to replace it with a brand new one from the dealer.. this will happen as soon as one comes in, but I think it's pretty safe to say that it is unlikely that the all three sensors should be giving the code for the HEATER only.

Do you think it is possible that the previous owner ran the car so long with the bad o2 sensor and CEL on, that it permanently burned into the computer's memory? Sounds crazy, but it does seem logical. I mean it comes on EVERY time only on the SECOND start w/ the same code.

Has anyone ever heard of anything like this happening before?

This is driving me crazy, not to mention making me broke

Anybody have any suggestions or advice?

 

Instead of wasting money by guessing, how about a little diagonstic work. What you need is a repair manual and multimeter. The sensor has 4 wires, two of them is for the heater circuit. You can use the manual to find out. Disconnect the sensor and measure the resistance from the 2 wires on the sensor. If there is no continuity or high resistance, then your sensor is defective.

 

Or someone who has the manual just pdf or scan the pages, that's one of the benefits of the web. Why make everybody pay for the manual only to make Nissan rich? Of course I do have standards and draw the line with software in the corporate flavor!