1995 Q45 O2 sersor advice

[jnever1]

I've read and digested the many posts on the topic of replacement of the 4 O2 sensors on the Qs. I now know that a good soaking in WD-40 or other lubricant is in order as is the purchase of a 7/8" sensor socket and an equivalent offset crow's foot socket. I also now know that a several extensions on universal adapters may save me cuts and bruises and most importantly TIME.

I've done some parts research using key words found in the replacement procedure posts such as NGK and Bosch. I've noticed two camps of parts available: the OE direct replacements and the 'universal' type.

Several of you have mentioned using both Bosch and NGK branded sensors. How has your experience been with the universal types?
Are the Bosch OE parts with OE harnesses worth the premium price tag?

Since my understanding of O2 sensing circuits is that they rely upon concepts of variable resistance, I'm curious about other's opinions regarding these 'universal' types of parts. Is the reduction in cost worth the addition of cutting/reconnecting wires? How does this potentially increased resistance affect performance?

I have yet to replace them on my Q since taking ownership from my grandfather who bought it new. I am pushing 170K and doubt he ever changed them. No check engine light but I get a 'check wallet light' every time I dump $70 worth of 93 octane into my tank (weekly). I would like to keep it another 3~5 years while I attend university.

I'm a chemical engineering major so feel free to drop as many technicals as you deem fitting.

Recent work: (within the last 12 months)

Stillen pop-charger (conical air cleaner... no more bubble box!) + duct mod to deliver cold air from hood bezel rather than from behind the headlamp lens.
Starter - Thank you NICO members!
Alternator - Thank you NICO member!
Radiator - thanks to a crappy shop, see head gaskets below
Idler pulleys - both
Fuel Pump - Thank you NICO members!
Head gaskets - both banks (got 1800 $$$crewed by a shop :-( that damaged my radiator in the process and pulled a Bill Clinton when confronted)
Plugs/Wires
Plenum Cleaned
EGR/PCV/MAF clean
Throttle Body clean
transmission Flush
Rear Diff flush
Fan clutch - tomorrow :-D

Fully synthetic since 2005.

Your guides and info have been spot-on so far (even the one minute delay to get my seat mem to start working again!) and I have come to value NICO opinions and knowledge foremost.

Also, part numbers for each of the 4 sensors if you have them, or wiring configurations (DF - 4 wire, PF - 3 wire, etc) would be highly appreciated!

Thank you!

[qship96]

first off,every 90-95Q only has 2 oxygen sensors, the 1996 model Q was the 1st to go to the 4 sensors as a requirement of the OBD2 system.Get the NGK/NTK direct fit models, plug and play,and they are the original part that came from the factory,purchase here for a very good price http://www.sparkplugs.com

You may be disappointed to find your MPG does not budge an inch if your current sensors are still operating{check for codes} I replaced my original sensors at 203,000 miles [they were not throwing any code} thinking the same thing 'they must be tired after 203,000 miles"....neither mpg nor performance changed one bit, NONE.

[jnever1]

My apologies. I assumed, since the car was sold in California in the mid 90s, that it would have been OBDII. My father is a Master Mechanic with a certification list more decorated than a WW2 hero. I should have looked for the DLC but my OLD(man) usually provides better information than any code reader so I didn't bother. For example, he nailed my fuel pump problem from acceleration performance without knowing about the "buzz-of-impending-doom".

Autozone also mentioned 4 sensors when last I priced them. I don't buy major components from them, but I find searching through their behind-the-counter catalog for odd-ball gaskets and such more convenient than the net. Just goes to show you how treacherous not researching your problem can be! It's also nice to speak with people rather than simply type all the time.

I decided to check the ECU for codes and confirmed that replacing my O2 sensors is not necessary. Based on this information and your advice, I will wait on the O2 sensors. Unfortunately, my Q threw a code 34 at me instead: knock sensor(s).

I'm heading over to a junk yard tomorrow to pilfer what I can from the only salvage Q within 100 miles. It is a 98 as opposed to my 95, but many parts appear interchangeable.

I intend to pictorially document my knock sensor change-out since I've only seen ParanoidJack's post on his 02 and the post from FarFetched. I'll see if I can throw up an article caliber post on the matter after I recover from likely 6-8 hours bent over my fender.

Thanks for the reply.

[OwnerCS]

Here's a thread with some of my older posts on O2 sensor replacement with pictures.

Some tricks in here might save you some work along the way.

post5945561.html?hilit=sensors#p5945561

[rabsusa]

I'm heading over to a junk yard tomorrow to pilfer what I can from the only salvage Q within 100 miles. It is a 98 as opposed to my 95, but many parts appear interchangeable.


Thanks for the reply.[/quote]


If its a 98 then you would be wasting your time, not much mechaincally in common, and nothing body-wise,
- unless struct brace fits?? those who have that mod can chime in
R

[jnever1]

...not much mechaincally in common...

It would be those parts that ARE common, particularly sensors, the knock sensors, maybe the O2s, the MAF, that bloody fan control amplifier right after the blower motor, that I am interested in. Parts, however, are my secondary purpose.

My main purpose is PRACTICE. This yard has a Q there for me to practice dismantling/reassembling. This is $2.00 for experience and invaluable knowledge.

Again though, thank for the replies.

[Q451990]

Good for practice, but I doubt even that list of parts is compatible... especially the MAF.

Heath

[jnever1]

Two things came from my experience:

First and foremost, knock sensor replacement is beyond my abilities. Sure, I can pull it all apart without a hitch, but keeping everything organized in a car-port, by myself, requires a commitment in time and organization that my workspace simply does not permit.

The second thing is the miraculous disappearance of my CODE 34 while driving to the yard and back. I'll check it again in a week.

MAF was not a direct replacement, as noted by Q451990. I didn't have time to bother with the O2s. The fan control amplifier was caked (as was the ashtray) with what I can only loosely describe as horrible, nicotine diseased, festering, pustulous grime. I'll probably catch cold just from looking at it!

I did come back with the knock sensors and wiring harness which were all in excellent shape.

The 98 had a strut tower anti-sway bar though... would this fit my 95?
I'll do my own search but figured I'd ask while typing.

Jerimiah

[rabsusa]

Two things came from my experience:

First and foremost, knock sensor replacement is beyond my abilities. Sure, I can pull it all apart without a hitch, but keeping everything organized in a car-port, by myself, requires a commitment in time and organization that my workspace simply does not permit.

The second thing is the miraculous disappearance of my CODE 34 while driving to the yard and back. I'll check it again in a week.

MAF was not a direct replacement, as noted by Q451990. I didn't have time to bother with the O2s. The fan control amplifier was caked (as was the ashtray) with what I can only loosely describe as horrible, nicotine diseased, festering, pustulous grime. I'll probably catch cold just from looking at it!

I did come back with the knock sensors and wiring harness which were all in excellent shape.

The 98 had a strut tower anti-sway bar though... would this fit my 95?
I'll do my own search but figured I'd ask while typing.

Jerimiah

you ;ll need to pull parts from 90-96 cars, the 97 thru 2001 are a WOS - waste of space,,, i m going to be scolded again, but i bought a 94 next to new, when 98 came out i drove it brand spanking new - i thot it was junk back then,
heavy, underpowered wth a weight to bhp ration close to a merc s320...ever driven one of those, slow a$$ $hit, so you can practise all you want, we just want to save you from wasting your time.... only gays drive Q45 97-01 and think they re it

[d.bright]

jnever1, I just replaced two O2 sensors on my '96 last Thursday. The front drivers-side ended up being the easiest, just got an extra long 3/8ths extension, crows foot O2 sensor socket and had a buddy hold it from the top while I guided it onto the O2 sensor, 30 minutes, done. The rear took a lot of coating with PB Blaster, using a 22mm wrench (closed end), beating on the side with a hammer, then repeating the whole process for about an hour. A couple of tips:

1. If the O2 sensor is hard to get out, make sure you use a tap and clean up the threads before you go in with the new one, it takes a few extra minutes but it is worth it.
2. I'm not sure if it's like this on the 95, but the 96 has a heat-shield covering the rear O2 sensors, 4 10mm bolts hold it on, remove it before you start removing the sensor.

Let me know if you need any more advice.

[3Q Jay]

Jeremiah- those ks off the fgy33 are the same, so you are good to go there. i normally would not recommend a used part on something that is a wearout item, but if that junker really only has 100 miles, unless it had an overheat, or got water flooded (corrosion) you should be ok. harness at the other end is different, though. If you want to go on the cheap, you could prolly use the fgy33 harness if you scab on your old connector from the g50. not what i would recommend, just sayin.

[3Q Jay]

also, you can get an idea of the health of your O2's by either using the laptop consult like software, or using mode II of the MIL diagnostic. drive the car at 40 mph (or if you must, hold 1700 in warm park in your driveway) look to see how frequently the O2 swings. should be more than once a second. once every 5 sec would be a lazy O2.

[jnever1]

Can anyone suggest a place to buy this knock harness? I've exhausted my normal resources, including some unusual ones found in the NICO forums. I have no idea who this "Joe" person is with the magical cave of discount infiniti parts either. I've found what I believe is the part number: 24079-60U71 since my Q was originally sold in California.

I really wanted to do this inexpensively, but it looks like the Q is (as usual) not giving me the option. The next best thing in my mind is to 'do it right.' I'm ordering new O2s and knocks from amazon.