rear o2 simulators?

My next little shop project is swapping a 302 ford (96) into a 1982 chassis.

I want to use the EFI, wiring and plumbing isn't an issue,

1982 doesn't require cats, Dual exhaust with an x pipe is desired

Does anyone know how the rear o2 sensor simulators work? I don't want a check eng light on constantly.

Thanks in advance folks

I'd think you would still have a check engine light unless you swap over all of the evaporative emissions related hardware as well. The catalysts are fairly minor in difficulty.

If you're doing a full exhaust, can't you just weld in a bung for the O2 sensor in the factory location and use the '96 O2 part?

I'm not sure how this one works specifically, some are just a resistor of a value that the O2 sensor would put out if everything's A-OK, some use a diode (sometimes with a resistor as well), and some need a full microprocessor board that simulates sensor output. For a vehicle of that age it's probably one of the first two.

Spark plug defoulers. Use your google-fu, good sir.

www.diyautotune.com

Edit: just run it on megasquirt

Knurled wrote: I'd think you would still have a check engine light unless you swap over all of the evaporative emissions related hardware as well. The catalysts are fairly minor in difficulty.

This, you want obd1, something hilariously hackable(GM), or standalone for this reason.

I seen the sparkplug defoulers, that just seemed to easy, and Megasquirt, I've looked at it multiple times, but I am a little intimidated, not in my skills, but in the tuning/operation of it.

warpedredneck wrote: My next little shop project is swapping a 302 ford (96) into a 1982 chassis. I want to use the EFI, wiring and plumbing isn't an issue, 1982 doesn't require cats, Dual exhaust with an x pipe is desired Does anyone know how the rear o2 sensor simulators work? I don't want a check eng light on constantly. Thanks in advance folks

I would think that you could use an OBD I computer on the car and not have to deal with the downstream O2's. By just repinning the ECM plug you should be able to use a A9L or similar EMC from a Mustang.

IF you want to go with what you have just search on "MIL Eliminators" and you should find the info you seek.

OBD2 computers are easier to troubleshoot, it's better and far easier to hook up some kind of simulator (1~4 pins instead of dozens for the ECU).

Typically the rear O2 will generate a check engine light if it detect a loss of converter efficiency. This type of code is annoying but doesn't effect the performance of the engine.

I have used rear O2 simulators in the past on OBDII systems. Works like a charm except most OBDII ECU 's also look for current draw on the O2 heaters.

If your O2 simulator circuit has a dummy load then your golden, otherwise you also have to wire in some high wattage resisters.

O2 simulators generate a variable voltage signal that osculates up and down to simulate actual operating conditions.

Spark plug de-foulers work best on OBDII cars that have had the cats removed. The de-fouler limit the amount of exhaust gas that the rear O2 can sampled and produce the appropriate leaner signal.

You can just swap the O2's from left to right. The PCM is looking for a mirror img of the front O2. If the PCM does not see it no light on.

GVX19 wrote: You can just swap the O2's from left to right. The PCM is looking for a mirror img of the front O2. If the PCM does not see it no light on.

that doesn't sound right to me...

what would swapping the O2's accomplish?

the front O2 sensors tell the computer how the engine is running, the rear ones just tell it that the cat converter is still there and functioning and that you aren't raping Mother Earth every time you drive your car.

and where do the spark plug defoulers figure into this? i know they will thread into the O2 bung, but can you fool an O2 sensor by putting a defouler in there?

The defouler gets the sensor out of the gas stream ad into dead space, keeps it happy enough.

In reply to novaderrik:
In 96 the PCM did not look for a lot of info. It looked for this:

http://i287.photobucket.com/albums/ll154/arghx7/cat_efficiency.png

If I'm wrong it was free And EZ just uncross the wires.

novaderrik wrote:

GVX19 wrote: You can just swap the O2's from left to right. The PCM is looking for a mirror img of the front O2. If the PCM does not see it no light on.

that doesn't sound right to me... what would swapping the O2's accomplish? the front O2 sensors tell the computer how the engine is running, the rear ones just tell it that the cat converter is still there and functioning and that you aren't raping Mother Earth every time you drive your car.

Not going to comment on cheating OBD...

But most OBD set ups really look for switch ratios- how often do the back sensors switch relative to the front ones, and at what rate is that when the emissions is 1.5x the certified standard. Realiscially, swapping from bank to bank won't make any difference, since it's quite rare that 1) the two banks are actually that far out of sync, and 2) the front and rears will not be in sync either- even with a dead cat, there is transport delay.

The rear O2 sensors can be used as feedback control on top of the front sensors. Works great. Very powerful took when used correctly.

GVX19 wrote: You can just swap the O2's from left to right. The PCM is looking for a mirror img of the front O2. If the PCM does not see it no light on.

If the rear O2 mirrors the front O2, that means the cat isn't doing anything.

double defoulers are perfect. My wife's car is catless with big injectors and zero cat codes ever in more than 5 years of abuse. Gets ready and everything. Oh and $5 at your local auto parts retailer.

i knew they sold those stupid defoulers for some reason... of course i'm sure that the nice folks would discourage anyone from using their products to defeat the emissions controls of their car...

Oh totally, this is for off road use only! For getting a so you can pass the obd2 portion of tech inspection.

Dont forget your 1/2" drill bit for the top one!

carbon wrote: Oh totally, this is for off road use only! For getting a so you can pass the obd2 portion of tech inspection. Dont forget your 1/2" drill bit for the top one!

i work in a machine shop... we have a lathe for things like that..

I will definitely try the defoulers first, i'm not ruling out megasquirt, but just not right now, I'll need to drive this as soon as possible. Thanks for all the info and opinions folks

When you decide to go with MS, let me know I have some with BT for sale. Cheeeeeeep.