Rear O2 sensor Sim install (1 Viewer)

[concretejungle]

Been fighting a PO420 code ever since i put the new exhaust on. Took the plunge and purchased Lilevo's rear simulator.

I will admit that i was intimidated by tapping into the wires. Anything electrical for that matter is intimidating to me. I do have some RC toys and have soldered wires many times, but still, i hate wiring.

I will also admit that when i first got the SIM there were no instructions. So i pm'ed him and he sent me a link to some pictures and wording saying Red wire on SIM to this and White wire to White, ect....

Still when you look at all the wires it's hard to figure out which one's he is talking about. He has since put some wording and arrows on the pictures helping to better identify which wires you are after. This actually turned out to be a HUGE problem since there are two blue/black wires on the same plug and you are supposed to tap into the blue/black wire.

Of course i tapped into the wrong one which gave me no power to the unit. We couldn't figure out why i wasn't getting power, so each time he said to remove the wires and test them on a battery or i decided to recheck my connections.... this resulted in me stripping wire shorter and shorter until now i have litterally no wire to work with.

Now, i think i have found the correct wires, but now i have a mess on my hands. Since the blue/black wire i tapped into was wrong, i had to reconnect that one and cut into the other blue/black wire. When i realized the wire was so short i didn't have much to work with but have a hand full of the little metal tips that fit into the plug, i thought i would just replace it.... WRONG! I tried for two hours to get the damn tip of the wire out of the connector with no luck! Then i had JFZ80 try, no luck. By this time the connector is getting pretty picked at and starting to look screwed up. Still today after another hour i can't get the connector out and my truck will not start.

I'm pretty damn frustrated and know that all this could have been avoided with better pictures of which wires to tap and me doing a better job of tapping into them. I blame this on us both.

A few pics here.. First is showing the bolt to remove the cover to get to the wires. Second is me pulling the wire plugs out to get access to them and locating the wires. The third is how i sit right now...

 

[concretejungle]

here is a picture of the connector.

Keep in mind there are two blue/black wires. You are looking for the wire that is in the corner position, not the one that is 3 over from the corner.. Just FYI

 

[NLXTACY]

Is there a relevant thread to get the back story? I have no idea what you are trying to do and why.

 

[concretejungle]

I'm trying to install a rear O2 sensor simulator to trick the computer into thinking that the CAT is stock and there is no insufficient flow.

Many who put on aftermarket exhausts get the PO420 CEL which states that the CATs are not working correctly or that the o2 sensor is not working correctly. It is simply a result of higher flow across the rear sensor due to less restrictive CAT or no CAT for that matter.

This is like a little micro chip that will fool the computer into thinking the rear sensor is doing it's job just fine even if there are no CATs in place.

 

[concretejungle]

So here is my problem....

 

[NLXTACY]

The pins are actually pretty easy to remove. And you will kick yourself once you realize just how easy

That being said, you can actually get replacement pins from Toyota. I would 100% replace that because it will cause you problems for a long time to come. Even if it means replacing the whole connector, I would. But that could be the OCD in me.

 

[concretejungle]

I know they are supposed to be easy! I replaced them all and the connectors when i had to extend the wires for the supercharger... So that's why i figured this would be a breeze! Now i can't for the life of me get this damn connector out.

That seems to be my last hurdle in a finish install.

 

[blkprj80]

PM sent. I have the connector as scrap and you're welcome to it! De-pin & re-pin will suck, but the housing will be nice.

Did the mating side get wrecked too? I hope not.

 

[blkprj80]

Hey CJ, here are some pics of your new connector.
As I said in a PM, the color code is way off.
You can also see the broken tab. I believe it latches, but you might want to defeat that since the tab is gone. Otherwise, you might only get one chance.
Do you agree this is the correct connector?
This one is from a 1996 OBDII truck.
It'll be in the mail on Monday.

 

[concretejungle]

Thanks! Based on the colors it looks like its the far left plug you have but I think they are the same pattern. I can just splice each wire and go with it.

 

[concretejungle]

Sorry for the delay in finalizing this. First off, i will say that because i'm not the best electrical guy in the world, this small installation had me nervous.

When "tapping" into a wire, it's not necessary to cut the wire. I found that if you can strip a section of the wire, then take the SIM wire you are trying to tap into the main wire with, wrap it around the exposed wire you just created, add a little dab of solder, then electrical tape to protect it, you are good.

Where i screwed up was cutting all the wires.

With that said, i finally ended up getting it installed and drove it last week to the coast and back (about 12 hours round trip) along with starting and stopping on the ferry rides, beach driving, camping, ect.. and no PO 420 light. I also noticed a much smoother idle and no power lag like i had before.

 

[BlackLS1]

nice job, glad you got it fixed. but from my experience, you can also install a spark plug anti fouler on the rear o2 so it doesent sniff the exhaust too well. that has worked on other cars.

 

[concretejungle]

Now for a few pictures.

First off, lilevo has supplied better photos with labels showing which wires you are after.

In the first pic of the thread you can see accessing the wires you need by removing the little speaker panel on the PS front of the truck with one screw/bolt.

Once it's off, you can see the ECU sitting there. There are, i think, three main plugs in the bottom of the ECU. You are looking for three wires in all those wires. Here is where lileveo's pics come in handy.

http://lilevo.com/cars/turbolc/O2sim/

With that said, there are two brown wires on the "LEFT FACING PLUG ON THE ECU" but only one of the two have a black tracer line on it. That's the one.

In the "middle" plug you will find a white wire. I noticed on mine there were some silver markings on it. Not really a tracer and no real pattern, but i did find some silver markings, just FYI.

On the right most facing plug you are looking for the blue/black wire. CAUTION!! there are two blue and black wires. You are looking for the wire in the far right corner (take a look at the pic in lilevo's pictures).

When it's mounted correctly, you will have a red light showing power and a blue light that modulates showing it's working correctly. (Pic attached).

I mounted mine with a piece of velcro stuck to the ECU.

 

[concretejungle]

to bring this thread full circle, you can see the plug that blkprj80 posted up. Thank you again for your valient efforts!!

I have attached a few photos showing the wire lock mechanism on these plugs. Had i known these were there, it would have saved me a lot of time and a lot of headaches.

I personally think it's easier to pull the wire you are after out of the plug housing and then work on it. To do this, there is a large, square "plug lock" on the bottom of the plug. You use a little pic to pull it up ever so slightly. Once that's done, you can use a little pic to reach in where the metal wire tip is in the plug, release the small plastic latch (pick the latch upward) and pull the wire out the back.

Don't remove this lock, just lift it. I removed it in one of these pictures just to show you what i was talking about.

 

[concretejungle]

If the SIM is working correctly, your rear oxygen sensor will be going between .75 and .00. Mine occasionally will jump to .76 and a few times .80, but it always will then follow up with .00. I am reading these measurements through the ultra gauge i have installed.

Anyone with aftermarket exhaust should install one of these. If you plan on opening up your exhaust for better flow, you will get a PO420 code. The only fix i have found that works is to either put restrictive cats in place or put a SIM to trick your sensor.

Good luck!