AEM WBO2 Install with AFR Gauge and O2 input to AFM/DME

[FA-18C]

I have read a zillion threads on various installs for a WBO2, and have my arms around the basics. BUT, I cannot find a clear answer to the best way to complete the install.

In general, I am installing a Dansk Euro Pre-----muffler in place of the CAT on my '88 3.2. Have an AEM WBO2 controller with analog output that will route to an AFR gauge John Bell made for me. Here are my questions:

1. I will figure out how to get the harness into the interior, and right now plan on mounting the controller under the seat near the ECM. The controller only needs Power and Ground as I am not datalogging.
Q - can I tie into an ACC PWR and ground for the seat for the controller? Or should I run the entire harness and output up into the instrument panel?

2. Output to the AFR is 12V and Ground to two spade connectors. So I need to get those two wires to the OIL PR and TEMP triple gauge I had made.
Q - Recommendations on getting the wires to the gauge?

3. There seems to be some debate on keeping the existing O2 sensor connection input for the AFM and DME, others say that with removal of the CAT, as in Europe, no need to connect the O2 sensor. Have also seen both sides of keeping or deleting when using a SW911 chip for the pre-muffler set-up.
Q - If it is recommended to keep the output from the WBO2 as an input to the AFM and DME, how is that accomplished? The output harness has a different connector for the output to go to the controller, and then the analog output goes to the AFR gauge. The other part of the harness is just power and input for datalogging (I think).

Q - In reading some have offered to return a line as an input to the DME. How is this done?

Q - alternatively, is there any sense in welding in a 2nd bung and offsetting the O2 sensor from the WBO2 and leaving the existing O2 sensor output as stock, and run the WBO2 based on recommendations from people smarter than me?

Apologize if there are hidden answers in various threads scattered throughout the board. But is becomes rapidly confusing (to me), and I really want to do this install once, and correct.

Thanks!

[jrwilson]

I recently did this and the wire from the O2 sensor to the controller was long enough to make it to the trunk, so I put the controller behind the dash.

I don't have a Lambda car so there's no other O2 sensor to worry about, but everything I've read says to keep them separate.

[FA-18C]

jr - how did you route your harness to the trunk?

[jrwilson]

Through the tunnel via the hole where the speedometer wires come in.

[FA-18C]

All the way to the front trunk area? I guess I need to crawl around my car and learn where all these wires go

[jrwilson]

I used a fish tape run from the front to the back, then pulled the wire back up to the front where it could route with the rest of the power cables into the trunk. It actually wasn't too bad.

[sigchuck]

For my '83, I used an Innovate controller. and went in through the speedometer wire grommet as well.

The sensor cable that came with the controller was long enough that I could go through the tunnel and into the cabin - I actually was able to bring mine up through the engine tin and then back down past the dust seal following the route of the SC fuel supply and return lines.

There's a small cut out in the tunnel just to the right of the console (near where the left side of a passenger's left foot would be) that you can access by pulling up the floor mat carpet and reaching under the edge of the carpet piece held down by the console. it's also probably necessary to remove the shift coupler cover to help things through. Probably much, much easier also with passenger seat removed, but I didn't.

For the wiring from the controller (mine is under passenger seat because I powered it via the original lambda system relay), I ran the ground and signal wire through the power antenna grommet into the frunk and then to the back of the John Bell gauge. I asked Innovate if there were any concerns with radio interference, and while they advised against my set up, I did it any way after I compared the readings with the wires ran next to the antenna, and without.

Also - can't say enough good things about John Bell. Amazing product and extremely patient - there was much back and forth and an exchanged gauge before I realized the AFR gauge needed 12v - not just the voltage supplied by the signal wire (DOH!!).

[FA-18C]

Sigchuck
My afr gauge has 3 spades for the gauge but the arm has 2 wire for the signal, I have an AEM. Will have to ask John on this.

[sigchuck]

My controller has two signal wires. I think most do with the difference being the voltage output of the signal that varies with the reading. You should be able to get that from you manual. Below is the excerpt from my manual:

The default analog outputs are as follows: Analog output one (yellow) is 0V = 7.35 AFR and 5V = 22.39 AFR. Analog output two (brown) is 1.1V = 14 AFR and .1V = 15 AFR.

I’m not sure if these are universal values or not. John would probably be able to tell you if you can find which wires send which voltage range.

[FA-18C]

I know he built it using the AEM table for 0-5V. Just wondering about your comment that the gauge needs 12V. Do I need another 12v wire to the triple gauge…

[FrankM_]

If you want to give the input back to the ECU be aware that it expects a narrowband signal so a rather drastic swithchover between 1.1 and 0.1 Volt between 14.x en 15 AFR.

See the 'second output' that "sigchuck" is using in his reply.

Do not give the 0-5V signal to the ECU !

[FA-18C]

Frank- amen that is what I want to be careful with.

[icarp]

Chris , I have my UEGO mounted in the 123 collector , The pig tail runs along the underside of the tin, then down the fuel lines and into the speedo grommet through the tunnel and up the foot wall , there is a hole that goes right up into the back side of the dash near the clock hole and has enough wire to connect to the gage .
This is for the AEM AFR set $200? https://www.amazon.com/AEM-30-0300-Wideband-Sensor-Controller/dp/B0184TSI84/ref=sr_1_3?keywords=aem+wideband&qid=1675976469&sr=8-3

[PeteKz]

Sorry to pull this thread a little bit. I want to do the same thing and install a AFR sensor and gauge in my 1973 with 1979 CIS engine (stroked to 3.2 with M1 cam). Is AEM as good as any, or are there better options?

[rswannabe]

PeteKz - AEM is generally well regarded. I went with Innovate as I already had one of their units and wanted to stay compatible. Innovate does not have as good a reputation as AEM in the Microsquirt forums.

FA-18C - Most O2 sensors are VERY susceptible to electronic noise. They also CAUSE noise due to their heater elements. If feeding into an ECU, generally you want them on a dedicated circuit, switched by a relay, and not on a power or ground feed shared with any other electronics. As your gauge likely is not providing decimal accurate read outs, it might not be as much of an issue. But if you really want accuracy (and why are you installing it if you don't want it to be accurate), follow the install guidelines which almost certainly say dedicated circuit on a relay.

[FA-18C]

I carp, yes just the controller. Had John Bell make a triple gauge. I am trying to resolve whether to figure out a feedback for O2 sensor input when using a Steve wing chip and no Cat. Problem is AEM sensor output is 0-5V and DME is 0-1V. So my perception is that I may need to weld in another bung and use both. Accomplishes both goals.

[FA-18C]

Rs analog gauge so really just want to make sure I am in the ball park for making adjustments. I can also later run the other outputs to a data logger module. First things first.

Sadly I need to deal with clutch first, it crapped the bed and was flatbedded to local small shop 😁

[scarceller]

The AEM 30-4110 has a special rotary switch and this allows the gauge to output 0-5vdc or simulate a narrowband 0-1vdc signal. The output line is the thin white wire. But the gauge can not do both, you need to decide 0-5vdc or 0-1vdc. If you run no cat converter you have no need to send any feedback to the DME. Just leave the stock O2 harness disconnect and the engine runs just like ROW engines that have no cat.

The 0-5vdc signal is also what you likely want to feed the special gauge created by John. You need to give John the mapping values that correspond to the AFR number for the given voltage output. Goto AEM site and get the user manual for the 30-4110 gauge and in that manual it has the voltage mapping chart for AFR.

You MUST provide a solid ground and power source for the gauge, do not wire it to the seats! One decent source is the cigar lighter, if you don't use that you can repurpose that line to power the gauge. But the best solution is to run a power wire with an inline fuse directly to the fuse box in the trunk, then wire it to the fuel pump fuse on the hot side. Or the ignition coil fuse.

If you contact me sal.carceller@cox.net I'll send you a AFR test case doc that outlines 7 important testcase for gathering AFR numbers to check the current health of your engine.

Enjoy!

[FA-18C]

Sal - I have the AEM 30-0300 controller, and John set it up for 0-5V. After considering all of the options, based on also installing a Wong Chip, I plan to use the existing bung for the current O2 sensor, and weld in a 2nd 1 inch aft and offset from the existing for the WBO2 sensor. I think this will solve my install intentions for the AFR gauge info from the AEM WBO2, and after resetting the idle settings following chip install, providing the feedback. I have read ALL of your posts, and if not running a chip, would just unplug as you say. May end up there anyways as I have a bung cap and will experiment as I go along to see if there is any driving differences all around.

I full plan to utilize the digarette lighter for the power here - that was from one of your other posts. I have never and will never smoke, so will reutilize that knob for a footwell light project I am working on. So power will be AEM controller only. I have John's gauge that has 3 spade connectors for the AFR, the outboard are labeled + and -, still waiting to hear back on whether I need to provide 12V to the center to power the AFR portion of the gauge.

I have your set up docs, and plan on using them. When I make future decisions on an engine rebuild, I am seriously considering your MAF set up. Have spoken to many folks that sing your system's praises.

Was hoping you would chime in, thank you.

[scarceller]

The stock O2 sensor is ONLY ever required if you have a cat converter. These engines run far better without the O2 connected, especially at idle. The O2 was added as a requirement to meet USA emissions, it causes idle and part throttle low-load cruise conditions to hit the 14.7AFR target. But these engines hate to idle at 14.7 they idle far better in the 13.8 to 14.2AFR range. If you get a WBO2 gauge you can actually play around with this testing. Get engine fully warm, unplug the stock O2 sensor and adjust the CO adjustment screw on the air meter so you hit 14.0AFR. Once that's done, with engine still running plug back in the O2 sensor and listen to idle quality and watch what the WBO2 meter starts doing. You won't like the results.

Get that WBO2 gauge working and I'd be happy to provide you a AFR test sheet with 7 testcases that will allow you to verify the AFR conditions at idle, part throttle and WOT.

Enjoy!

Originally Posted by FA-18C

Sal - I have the AEM 30-0300 controller, and John set it up for 0-5V. After considering all of the options, based on also installing a Wong Chip, I plan to use the existing bung for the current O2 sensor, and weld in a 2nd 1 inch aft and offset from the existing for the WBO2 sensor. I think this will solve my install intentions for the AFR gauge info from the AEM WBO2, and after resetting the idle settings following chip install, providing the feedback. I have read ALL of your posts, and if not running a chip, would just unplug as you say. May end up there anyways as I have a bung cap and will experiment as I go along to see if there is any driving differences all around.

I full plan to utilize the digarette lighter for the power here - that was from one of your other posts. I have never and will never smoke, so will reutilize that knob for a footwell light project I am working on. So power will be AEM controller only. I have John's gauge that has 3 spade connectors for the AFR, the outboard are labeled + and -, still waiting to hear back on whether I need to provide 12V to the center to power the AFR portion of the gauge.

I have your set up docs, and plan on using them. When I make future decisions on an engine rebuild, I am seriously considering your MAF set up. Have spoken to many folks that sing your system's praises.

Was hoping you would chime in, thank you.