BLKROKT

Awesome man, thanks!

Going to try this now. Think my software was just really old. Will let you know.

BLKROKT

So, quick update. No joy unfortunately.

Updated the software, ran the SRS module, and I actually don't have any codes. The airbag light is on (the red one) as well as the warning when I start the car, but there are no codes to clear. Ran all modules, and same thing. Looks like I will have to take it to the dealer afterall, because if there are no codes, and the airbag never deployed, then I'm not sure why the airbag light is still on. Thanks for checking for me anyway mthis!

On a happier note, I have some preliminary results on the effectiveness of the radiator blockoff plate, and it is very very good for us (see thread here: https://mbworld.org/forums/c63-amg-w...your-cool.html )

mthis

was the car on or off when you tired scanning for code?

BLKROKT

I tired every combination man. Car running, no code. Car on key position 1, no code. Key position 2, no code. Restarted the software, computer, unplugged the connector, etc. A real head-scratcher.

The only codes I have now are related to my secondary O2 sensors (heater circuits) which I removed. Working on a solution to that also... will just leave this here until I can report back affirmatively on the 'fix'...

quaalude

Nice write up BLKROKT. Have you dynoed before these mods? Before and after would be cool to see the gains. I own a 2012 p31 coupe also and will probably do something similar as your setup except oe tune and row boxes. For the secondary O2's, couldn't you have just left them connected and have Eurocharged deactivate them with the software? If they're plugged in, then the heater circuit is complete and you wouldn't get a code. That's what I did on my CLK500 with Kleemann headers and tune. I welded some extra O2 bungs into the downpipe I made and just plugged them in.

BLKROKT

No before dyno unfortunately, but I do have 1/4 mile times which are more meaningful to me anyway. We will see how much I improve on my 12.1@117mph stock time in a few weeks when the tracks open up out here.

EC can shut off the cat detect sensor part, but not the heater part. I have cats. I also have bungs already on the MBH headers for the secondary O2s, but I plan on using those for my wideband AFR gauge. So I just disconnected the sensors, and now I'm getting code only for the heater circuit. I could have left them hanging zip tied outside the exhaust somewhere, but didn't know if they would even heat or function correctly that way. So now I don't intend on plugging them back in at all. My buddy suggested I do some research on the resistance needed to trick the ECU into believing that the secondary O2s were heating correctly. I figured 20ohm should do it. We will see.

BLKROKT

Update on this. It worked. CEL gone. No codes. Also no secondary O2s at all.

For those of you who want to get rid of your secondary O2s completely - either because your headers don't have an extra bung, or you want to use your spare bung for other purposes, or whatever - it's a simple fix.

This is for "offroad use only" of course. The fix is to solder a 50W 20ohm resistor (I used this one: ) into the heater circuit for the secondary O2. Tuners are able to turn off the 'sensing' part of the secondaries so as not to trigger a CEL, but are unable to turn off the heater part. This resistor tricks the ECU into believing that the heater circuit is functioning correctly - had to figure out how many ohms the heater circuit output to the ECU when functional, I think it's somewhere in the 12-40 range.

I cut off the secondary O2, electrical-taped and shrink wrapped the sensor wires (black + grey), then wired the resistor between the two heater wires (white + white). Wrapped all of it in plastic loom, reconnected plugs, and wiretied out of the way away from the headers.

Have gone through a bunch of cycles already, and problem solved. No codes, and no CEL. Was getting a code during the first couple of cycles, saying that the secondary O2 heater circuit status was "permanent", but it went away after about 5 cycles, and no CEL as a result either way.

MBNRG

Thank you, BLKROKT for another informative post
Although more 'specialized' knowledge, his technique for fabbing Secondary O2 Emulators should be a sticky.

I don't suppose it is common knowledge that Eurocharged Tunes (and likely other tunes as well), code out the sensor function, but do not code out the heater function of these O2 sensors.
For those of us wanting to use these Secondary O2 sensor positions to connect an AFR monitor (ie Innovate DLG-1, etc), his Emulator technique will be necessary, to prevent not only the subsequent CEL, but also the engine from likely reverting to a fixed map/open loop type operation.
Thinking more broadly, his technique may also help those running with LTH + Tune, and Heated Exhaust Gas Oxygen sensor monitor "Not Ready" faults during Emission testing

hadam3

Great write up! and work looks amazing... i always thought you already had headers!!!

BLKROKT

I’ve has headers on for 4yrs already. MBNRG just dug up an old thread.

hadam3

lololol.

BITRBO

Great write up ROKT. I'm planning to hit Daytona at the end of the month and will definitely be doing this blockoff plate mod.

Apologies if I missed it somewhere, but this is for the secondary O2's after the primary cats, correct? I'm planning to delete my secondary soon and assume there aren't any sensors there to contend with but just wanted to be sure.

MBNRG

Correct, BLKROKT's O2 Emulators are for the Secondary (Downstream) O2 Sensors for those running aftermarket Long Tube Headers + Tune.
This Downstream O2 Sensor is immediately after the Stock Primary Cat in a stock OEM setup, but this position can change on aftermarket Long Tube Headers (depending on cat or cat-less setup, X-pipe, etc)
If by 'delete secondary' you mean deleting Stock Secondary Cats - those have no associated sensors

brad65ford

Just checking to see if you ever got to run at the track to see new time difference with headers.

edit didn't realize the thread is so old, saw recent photos from a few months ago lol ;-)