Hi Guys,

I am looking at replacing my O2 sensor in my 85. I am looking at buying it from Rock Auto. The replacement sensor listed under their drop down menus list this one.
http://www.rockauto.com/en/moreinfo.php?pk=89393&cc=1041208&jsn=553 &jsn=553&jsn=553

However, the parts manual lists GM part number 8990741 and when I do a search for it I get this one.
http://www.rockauto.com/en/moreinfo.php?pk=1323881&jsn=564

Now, it is very possible that either one will work just fine. But, what would you do, buy the direct GM replacement, or the one listed by Rock Auto?

I also find it a little amusing that it recommends replace at 30K - 50K for this item. I have 90K on my car and I know it has never been replaced.
Thanks Guys.

 

randy, FWIW, I bought a bosch replacement O2 sensor for my 85, p/n 12014. couple years now, no issues. I would think either the Delphi or the delco would work just fine. probably the same part anyway - - I checked the ac delco site, and for the 85, they show AFS21 as the OE replacement. they also callout "professional" as delco "professional" number 213-1165. "professional" are usually 3rd party vendor supplied meeting original GM specs, so you have no idea of the source. could be Delphi, could be bosch, could be anybody.
BTW, had my original on the car for around 150K miles - - the only time I replace my O2 sensor is when replacing the exhaust.

 

Thanks Joe.

Yeah, I did consider the Bosch as well. Probably doesn't make a big difference at this point anyway.

Well, like you I have all the exhaust out of the car and since I had to drill out a broken bolt from of the Catalytic converter, well you know. Easier to replace now then when it is back in the car.

 

I use Bosch. https://www.autozone.com/engine-mana...70_399771_1784

Why is it amusing to ask for a replacement at 30-50K? Like everything, it does wear out and what it does is critical. Thing is, I suspect that like many others, you think it is a binary thing where it works or not. That is not true. It can get "lazy" and sometimes inaccurate. Like everything that progresses slowly, you often won't notice it till it is FUBAR. At which point, your SOTP dyno will finally do some work and pick up on it.

 

Actually in the grand scheme of things the Bosch is probably the worst O2 sensor made. Many have had far better luck with the Denso, NGK/NTK sensors should you ever replace them on any other car.
For an early C4 it probably doesn’t make a bit of difference what you use since its just a 1 wire O2 sensor.

 

I just replaced both of mine this past Sunday. Got them from Rockauto 212131165 Delco professional. I suspect the left one was bad but replaced both to take advantage of the economy of scale having half my tools all over the garage floor and number of swear words. MPG went from 14 to 21, no more smelly exhaust, and the idle improved.

 

It isn't the recommended interval I find amusing, it is the fact I had gone way past it and didn't realize it. You are far to cynical sometimes and just need to lighten up a little. Also, you could ease up on being so judgmental, it has no value to this forum. It is important to me to adhere to proper scheduled maintenance on all of my vehicles. This one just got past me like a couple of other things on my car. In fact, there are some things I may even over do, but I won't get into that right now. Some of these things aren't always easily found in the manuals or service sheets and can sneak by you at a particular interval.

 

Cjunkie, Please elaborate, why do you think so?

Chrly, the O2 sensor was the only thing you did to see this MPG change and how did you know it was bad? Lucky me, my 85 only has the one O2 sensor. Yup, good idea replacing both while you're at it. Isn't it satisfying to see confirmation in your hard work?

 

With my '92 it never went into closed loop and I found that the drivers side was lazy (voltage changed slowly). I replaced both with Bosch and now it works properly. I used a Snap On analyzer and TunerPro RT with a laptop and OBD I cable to confirm.

 

Well if you read other forums on other makes/models everyone seems to complain and not get long service from the Bosch O2 sensors.
There is no such thing as a Delco/Motorcraft/Mopar O2 sensor. They are either Denso,NTK,or Bosch. I don’t care what the box says there is no such thing as an AC Delco Professional today.
Everyone seems to like and get great service out of the Denso, NGK/NTK O2 sensors which are OE for the world (yes Ford/GM/Chrysler) except the Germans..........we all know how great their electrical systems are.
Now these are all 3-5 Wire heated O2 sensors and as I said on a 1 wire it probably doesn’t make a difference but if you can get a Denso,NGK/NTK for a dollar or two more go that route.

 

You should not realize it. That is the point of EFI. It compensates till it cannot compensate any more. This is why when people tell me "It runs fine.", I take it with a BAG of salt, not just a grain. They run "fine" till it is completely FUBAR, in which case, you notice it then.

I lived long enough to realize that the more cynical I am about people, the less disappointed I get by them.

I look at scheduled maintenance as a "LOWEST possible standard" since manufacturers don't want to give the impression that their cars are needing more work than the competitors. Often I would test the fluids to determine when they need to be changed. Why? Because while I know the manufacturer knows best, I don't believe they always tell the whole truth. Again, the cynic in me.

 

How long a life are you expecting? Also, when you say "long service", how was that determined? Change when the O2 sensor is FUBAR or they graphed it when it was new and replaced it when it got slow and/or lazy?

Absolutely true. The question is, while they come out of the same factory and get shoved into different boxes, are they made to the same SPEC?

Not sure. I have gone 477K, 170L and 150K on 3 MBs. What should I be looking for?

Or change to a 2 or 4 wire one.

 

OK, here is another question on this.

What do you guys think of using Neversieze on the O2 sensor when being installed? Will it damage the sensor? Sorry, I haven't checked the manual or seen the installation instructions just yet. Though, when I removed the old one it did come out just fine with no real issues.

 

On the threads, yes. On the sensor itself, no.

 

OK, not sure why anyone would apply Neversieze to anything other than the threads. I just wasn't sure that hot Neversieze vapors would foul or damage the sensor. Some of this stuff can be over sensitive to things like this.

 

Don't know but you never know what some idiots do. I don't think it will have vapor issues.

 

love some of the comments. now I don't know much about O2 sensors and i'm no expert, but let me point this out as general information. since Randy M. was originally referring to an O2 sensor on an 85 corvette, lets take a look at section 0B, maintenance and lubrication, within the factory service manual for the 1985 corvette. seems that the scheduled O2 replacement is strangely missing from that chapter and the service manual in general. now we do have schedule I and schedule II maintenance schedules, and within it's contents are the emission control service and schedule, which includes:

engine oil and filter
carburetor choke and hose inspection (if equipped)
carburetor or TBI mounting bolt torque
engine idle speed adjustment
vacuum or A.I.R. pump drive belt inspection
cooling system service
vacuum advance system inspection(some models)
spark plug and wire service
PCV valve inspection
EGR system service
air cleaner and PCV filter replacement
engine timing check
fuel tank cap and lines inspection
thermostatically controlled air cleaner inspection (if equipped)

those are the bulk of the emission control service as covered in the service manual at the 30K mile mark.

funny, maybe I missing something, but I don't see a friggin thing about replacing the O2 sensor at any interval. I guess that stupid friggin GM forgot to add that in my copy of the FSM, maybe I need revision A, or maybe they (GM) should have consulted someone with a little more knowledge on the subject.

the only thing covering the O2 sensor is leaded gas will damage, and code 44 and 45 (lean and rich conditions). now there could be issues with the sensor that may not trigger a code, such as poor performance, rough idle, poor fuel economy, and the sensor MAY be the culprit, but to randomly say an O2 sensor SHOULD be replaced at the 30K or 50K miles, IMHO is , but then again, i'm no expert! if i'm missing something, someone please point it out to me.

BTW, probably replaced a half dozen O2 sensors in my life, and as I recall, always bosch. can't say I've ever experienced a problem, but then again, WTF do I know....

 

Hey Joe, thank you for verifying that for me. I got the recommended change interval on the Rock Auto website. It was the first time I had seen such a thing.

http://www.rockauto.com/en/moreinfo....sn=553&jsn=553

Probably the manufacture just trying to sell more sensors. I am willing to give you more credit on what you know than you are. Thanks for the education. Keep up the good work.

 

You seem to think knowledge is the be all and end all of things. Doctors smoke. Do you think they don't know about the dangers of smoking especially when they tell the patient "Don't smoke like I do."? Just because GM knows it DOES NOT MEAN IT IS IN THEIR INTEREST TO TELL YOU. If they think that more service will scare away the customer to another one that reports less service needed, they won't tell you if they can help it.

You can do it one of two ways generally. Either replace on a schedule like your oil or test it. When I switched to synthetic on the Powerstroke, I doubled the 3000 mile interval and had it tested. IIRC, they said it would wear out in a bit more so 6000 is my interval. So, you can record how the O2 sensor performs in a certain set of conditions and check it every so often and see what the check and change intervals should be.

Without datalogging, you are right. What do you KNOW?

 

"You seem to think knowledge is the be all and end all of things" -

"If they think that more service will scare away the customer to another one that reports less service needed, they won't tell you if they can help it." -- WTF??? -

who defines the scheduled - you, or do you have knowledge of this secret maintenance schedule GM doesn't want me to know about???

50 million car on the road without datalogging, and I doubt 0.01% are testing and/or replacing O2 sensors on any kind of regular schedule. doctors and smoking, and switching the subject to oil and powerstrokes - WTF are you talking about?

i'm impressed with your comments, but then again, it doesn't take much to impress me.