Question about o2 simulators
 

I had to gut my daughters Converters on her 2002 Maxima. The firewall side was completely stopped up and the radiator side was completely empty. So all three are gutted. Do I have to install O2 simulators or will the car run like it is without running rich or lean? Just crank the car up in the driveway today but haven't driven it out yet and it hasn't set a code but there is white smoke coming from exhaust like it's running rich.

Most folks use O2 extenders on the secondary sensors rather than simulators as the simulators are difficult to acquire these days. The car will run fine as it uses the primary sensors on each bank to trim fuel so no, you shouldn't be running rich.

White smoke means antifreeze to me, which would be unusual. I'd expect to see black smoke if it were running rich.

some people can get away without doing any extenders or simulators but I used o2 extenders for mine.

does white smoke smell sweet?

This ^^^, and i am currently using the rare sims, gutted pre cats and they were 100 intact , unlike yours.

I gutted mine a few months ago. I purchased sims before I did the job but I didn't install them until I got a check engine light, which occurred about 15 minutes into the first drive. I got the codes for both cats, P0420 & P0430.

These are the sims I used: http://www.area74.ca/io2/

I put them right next to the ECU so the car still looks completely stock/ unaltered.

If your state doesn't require smog checks or vehicle inspections you could just go without sims and live with the CEL being on all the time or go with the extenders as the others have mentioned.

dude great post ! these things are hard to to find !! thanks for sharing, !! i may refer to this for other members needing sims,

and there is a great write up from Puppetmaster on the forums here for 2002 sim install

FWIW, I had a bunch of questions before and after installing the iO2 sims and the owner/developer of area74, Len, was very helpful.

They're somewhat expensive compared to what sims used to cost but they're the same price as the only other conventional sim I could find and I think they're much more sophisticated than a standard timer type sim.

Using the Torque app, it was interesting to watch the graphs for both secondary sensors before and after installing the sims. You can see how they change the curve and trick the ECU into thinking everything's wonderful.

i have an O2 sim right now and gutted cats for 3-4 years, and now I got the P0037 light yesterday after a long drive.

its Bank 1 rear sensor 2

is my SIM not working any more? i read up on this fuse you can check too, whats confusing is the sensor that is throwing a code is not on the Precats at all... any info guys it would be aweome, after I look over the fuses and not find anything, i am worried the sim is done =/


https://cimg0.ibsrv.net/gimg/maxima....e8d125f2d8.jpg


edit - i went as far as checking the o2 sim itself yesterday and it is blinking which indicates normal operation.

Depends on how your SIM operates I guess. I was doing some reading back when I was trying to make some... completely 100% unrelated electronic equipment that definitely has nothing to do with illegal SIMs... and saw that you also need a resistor to simulate the heater component of the O2 sensor. Are your secondaries still connected with the SIM modifying their signals? Or do you have your SIMs completely replacing the secondaries? If you have the sensors entirely unplugged, it could be that your SIM is satisfying the ECU's requirement for cat function, but is lacking the resistor to simulate the heater function. If they are still plugged in, it could be that the heater/resistor on the sensor itself has become faulty, or the wiring leading to it is faulty.

In any case it is a FAR easier fix to have an issue with the heater circuit that it is to have one with the cat function.

Thanks Slamrod, i am going to look into it, i know the secondaries are still connected w the sim modifying (tweaking) the signals. If the heater/resisitor is bad do I just replace the o2 sensor throwing the code? And thank you for that assurance that it is easier to deal with with the heater circuit vs cat problems I do agree. Though It feels odd tho and kinda contradictory to replace a o2 sensor that is being tweaked by a simulator though, it got me thinking how is that really possible. But i am starting to understand that the sim just tweaks the voltage on the cat reading not the heater

https://maxima.org/forums/5th-genera...tallation.html
here is the procedure I followed (thanks puppetmaster !), and by reading through it , i think you are exactly right because following that I left the heater wires intact (meaning they will still read right or wrong readings as is). can you confirm i just need a new o2 sensor (bosch) to fix the heater/resister fault? Thanks in advance!

Basically a SIM is a small circuit featuring an intergrated circuit chip. In this case the circuit uses a 555 timer chip to reproduce an oscillating frequency, iirc its between .05 and .09 volts - this is what the ECU is expecting to see from a working secondary O2, in an exhaust system with a working cat. Since your SIM is producing this rather than the sensor, you are not getting the code for it, because your ECU is happy with what it sees.

HOWEVER - your SIM does not simulate the heater element, which is simply a fat resistor inside of the O2 sensor. When current runs through it, it gets resisted by the resistor (obviously), and that produces heat. Thus why its called a heater. Since you are getting a code for the heater, it means your sensor has failed or at least the connection has failed. You are not getting a code for cat function, because your SIM is producing the signal to satisfy that requirement. But for context, if you hypothetically were not using a SIM, youd probably be getting that code as well.

Long story short it appears your sensor is dead. You can test this by removing the sensor but leaving it plugged in, and seeing if the sensor gets hot on its own. You may also wish to check the wiring and make sure everything looks good. I wouldnt worry about the SIM itself, if youre not getting the code for cat function it means the SIM is doing its job just fine.

Thanks a Ton Slamrod !

Found my old Cattman Headers O2 simulator wiring diagram that might be of some use to you guys trying to figure this out....

thanks man, reading now

alright, so the o2 heater fuse was ok (interior fuse box), and i will hopefulyl receive the bank 1 sensor 2 sensor in the mail today, i was reading up on the manual and it looks like i need some special socket to remove/replace the heated oxygen sensor? is this true?? i also read this
do i need to put on anti seize when installing the o2 sensor ? thanks for any info guys

The special socket is just a normal deep socket with a slot on the side that allows the wire to protrude out the side. You can just use a wrench instead, otherwise just cop one at autozone or w/e. As far as antiseize, every o2 sensor ive ever dealt with comes with some antiseize already applied right out of the box. If there isnt, all you need is a tiny little pea sized dab of the stuff. All its for is to make removal in the future easier, as the constant heating/cooling of the sensor can make it very tight.

thanks a ton dude !! greatly appreciate it, this all makes common sense in hindsight. lol thanks!

Tuning is also an alternative to O2 sims/spacers for modified cars for track/off-road use. Cheaper than sims, guaranteed to work.

https://cimg4.ibsrv.net/gimg/maxima....12979571d0.jpg
:)

ordered the freaking wrong downstream and it has diff connector and cord length, it had dark green vs dark blue, and they r not cross comaptible, trying again soon, i am happy i dont have to mess with any soldering or the sim at all because its after the o2 sensor connection

i returned through amazon, and they are freaking awesome, some how the new part showed up on my door today, i hope to give it a try today! thanks again all, will post results

i kinda know of SMD, but not much about it =) so i got the right o2 sensor on and installed, and p0037 light didn't go away yet after 30- 40 miles, i am hoping a reset keeps it away, i think you wanna makes some sims =)

IIRC the o2 sensor code reset is based on a number of specific cycles rather than a number of miles. For example, going 0-60 x number of times, driving at x mph for x amount of time, etc. However usually those criteria are met around 60 miles or so. You could also go to an autoparts store and ask them to scan your codes and delete them for free if you dont have your own scan tool.

i was hoping for that and thanks for the confirmation on the cycles, i wasnt sure what codes need manual resets or passive driving cycle resets, it should do it today after driving highway. i do remember my evap code took a few days of the commute i am doing now to have the monitors ready.

fingers crossed, if not i just wasted a sunday morning and 57$ on a downstream o2 sensor. also those stores really try not to reset, too many people would ask, i am ordering a scan tool now, its about time i get one. thanks again! im gonna study SMD today =)

ok so i got a OBD2 reader and erased the code after replacing the sensor, fingers crossed , it is looking like it is staying off ! been 200-300 miles !

I could be wrong on this, but I don't think the codes will clear themselves. After I installed the simulators I waited to see if the codes would clear themselves and they didn't. I cleared them manually and they never came back. You should be good to go.

Prophecy99,

Out of curiosity, what simulators are you using?

I am using sim from a online car part store that is around still but they don't sell simulators any more, I am using a dual sim (both banks), and it only does the signals not the heater circuits. did u want to know the actual brand name? I can look into it but its not existent now so =/ not sure if it matters , and the light is still off ! woo woo.

Sims are out there if you search I think I saw some on a Mitsubishi 3000 site..Hey Prophecy99 just clear the CEL and drive it you shouldn't have have any issues...the monitor ready is complete around 85 miles...I've been running Cattman headers for 10+ yrs with that some SIM placed in a thermal sleeve sitting on top the fwd valve cover but under the engine cover!

For the naysayers: http://www.area74.ca/io2/

yes it was 3sx , thats the site =) more geared for 3000 gt and dodge stealth guys, and i kinda want to get this thermal sleve now ! i have mine in same place as u, and i always worried about its kinda whatever location i placed it in, fingers crossed i am 3 years deep. and for anyone else reading, i cleared the light after 200 miles and it hasnt come back. good info to know about the 85 miles for monitors as well.
yes this is the latest site ! and one of the only u can currently find in 2018/2019

These are the sims I have. I think I did a write up on them after installing them.

I'm VERY interested. Do you want to share any of the details?

No touchscreen? No WIFI?

What is this crap?

Seriously, this is great. I hope it works.

You probably know this, but if you have a bluetooth OBDII adapter and an app like Torque, you can graph the output of your sims and see what they're doing. That would be cool to see.

Good luck. Keep us posted