FAQ: O2 (Oxygen) Sensor Information

Not sure if it was said before but unless you need the parts right at that instant, I'd shop online for them. Denso O2s are probably the best (better than Delco, IMO) and you can get them online for $40. As for a MAF, I'd just hit up Morad. I'm sure he'd sell a low mileage OEM one for a fraction of whatever NAPA wants.

GL

How about a used N* TB and LQ4 MAF.
Would you recommend used from Morads or just buy new from ZZP.????

I poked around rockauto and found a Denso O2 sensor for pretty cheap. Put the part # into google and found it for $35/shipped from Amazon. This seems way too good to be true. A buddy of mine just fell into this sort of situation and what he ordered was a universal. He said it had to be spliced onto the existing pigtail.

For AC Delco, I found the part # AFS109: Saw it for REAL cheap on ebay as cross-listed for a Chevy Express van?? Link

^^ That can't be right...

For Denso, I found part #234-4018 but I think that is the universal. http://www.amazon.com/Denso-234-4018-Oxygen-Sensor-Ratio/dp/B000C5WCOA

Anyone else order one of these sensors recently? I'm looking to save some $$

It *could* be right; there are some "direct fit" sensors that fit a family of applications (same # of wires and same plug on the pigtail) but the pigtails are different *lengths*. What you end up doing is lashing the extra pigtail length up onto itself with zip ties, near the plug (not near the sensor) end.

Albertj

The Denso sensor part# 2344018 that you listed shows on rockauto as an 'oe type', plus if you click more info it shows a pic of the connector end. I don't think that is a universal. Can't help with the Ac Delco but if you call your local dealer they should be able to give you a correct part number and possibly cross-reference it for you. Good luck.

For my $$ I'd buy the Denso, worst case is there will be some extra wire to cinch up.

Albertj

I saw the info pic too Derek and thought it was too good to be true. lol

Thanks for the help guys. Going to grab one now.

Rick - I recently had to order one as well, but I did it through Advance Auto. I don't remember the price, but the part number on mine was #234-4012 . I don't know how different that is from '4018', but I hope that helps a bit.

-Andrew Z

Andrew that part # is for the 95 model, 97 appearently is different. I'm not sure what's different but the delco and bosch also use different part #s for each so its definitely not a typo. We're actually lucky in that ours are cheaper.

My apologies - One of the few times I've ignored which year car I was looking at.

Rock-auto confirmed that it is direct plug and play. I have a Denso on the Regal and it reads much more accurately than the stock Delco.

As an aside-do NOT get a Bosch. I've seen a half dozen cats go bad shortly after changing over to one of those sensors. They don't seem to jive well with this GM setup. :/

So I'm thinking of getting an O2 sensor. I was planning on getting either AC Delco or NGK. Both seem to get good reviews and both are available at the parts desk up here. People here seem to swear by Denso, which is only available up here online. Also, NKG are 20% off this weekend at a part source up here, any opinions?

The AC delco I paid top $ for @ the dealer, shows its running lean with my scanner.Not being a diagnostician at all, I dont know what that means except it aint worth shit.when I had my Acura,I bought many NGK parts and not one ever failed. plugs wires etc..all super reliable. I didnt even know that NGK made for the Riv. I would take a chance on the NGK

got a denso in the riv and have had no problems. very responsive sensor, but it was replacing a 150k mile sensor so i dont really have a new "other" brand to compare it to.

So we should see the O2 in the 9s at WOT and around 4.5 when chilling?

< 4.5 and you are rich. less O2 and more fuel

> 4.5 and you are lean. more O2 and less fuel

Is that right?

Please educate me.

Thank you.

DEMonte1997 wrote:

Rock-auto confirmed that it is direct plug and play.  I have a Denso on the Regal and it reads much more accurately than the stock Delco.  

As an aside-do NOT get a Bosch.  I've seen a half dozen cats go bad shortly after changing over to one of those sensors.  They don't seem to jive well with this GM setup.  :/  

Damn... Recently installed a Bosch sensor..

@charlie
No. You have it backwards.

< 450mV you're lean

> 450mV you're rich

Lean means you have too much air and not enough fuel.
Rich is the opposite...not enough air, too much fuel.

At WOT, your O2 should read between 800mV-850mV.
Anything really above 850mV is considered too rich.
Anything under 800mV might cause a lean condition.

At idle, your O2 is going to be bouncing around everywhere. You can see the changes being made by watching STFT. The leaner you are, the more positive STFT goes, and the more rich, it goes negative. You can watch both of those numbers simultaneously on a scanner and see exactly how it works.

Thank you very much.

Yeah, I had it backwards. I thought the higher the O2 value the more oxygen in the mix = lean.

I've got a code P0141 "O2 Sensor heater circuit bank 1 sensor 2."  What part do I need to get and what do I have to do to replace it?

I would check the wiring and connector for O2 sensor downstream of the cat converter before replacing anything. Road debris can contact the sensor, causing this code.

I went ahead and did my manifold sensor today. Took all of 20 minutes (minus the time for PB to soak in). I used an O2 sensor socket that I borrowed from the mechanic up the street, and doing this job without it would suck. A lot. Here's pictures of the setup I used (socket, universal, long extension, medium extension) as well as the old and new sensors.

AA wrote:

I would check the wiring and connector for O2 sensor downstream of the cat converter before replacing anything. Road debris can contact the sensor, causing this code.

Finally got around to looking at the sensor - it looks clean as a whitle, no problems anywhere that I can see.  I'm looking at replacements on RockAuto and there are several available with a wide range of prices ($25-$81).  More importantly, we have UPSTREAM and DOWNSTREAM to choose from.  Which one should I get (97 SC   )

Once again the error code is "code P0141 "O2 Sensor heater circuit bank 1 sensor 2."

Just to be 1001% certain about this - the sensor I looked at looked like the one in matt270avian's post above, and was between the catalytic converter and the resonator.

You'll need an UPSTREAM sensor and Denso is the way to go.

Denso is the way to go. Sensor 2 means it's the post-cat sensor, but you might as well do both since they're not to expensive. Might be cheaper on Amazon.

Oops. Read right over "sensor 2".