Wideband Positioning in Stock Downpipe?

blk-majik · Aug 19, 2009, 03:33 PM

I'll be installing my wideband in a couple weeks. I've read the few threads on the downpipe removal and wideband bung welding threads. I'd like to leave the wideband in all the time, so I need to install it on the top quarter of the downpipe (unlike the most detailed bung install howto i've read). However, the factory front o2 sensor is dead center on the top of the downpipe, so I have to work around it.

Relative to the front o2 sensor, where is the best place to install the wideband? Would putting it directly upstream from the front o2 sensor interfere with the factory o2 sensor readings? Would being closer to the turbo be less than optimal due to heat concerns? How much space should I leave between the ends of the two sensors?

Also, would it be preferable to install it using a bung with a spacer or a flush bung?

Thanks!

empirepb210 · Aug 19, 2009, 03:44 PM

You can buy a test pipe that has 2 bunga built in already If you wanna go that route

blk-majik · Aug 20, 2009, 10:26 AM

That implies I'm going to be repalcing the cat and going catless. Two things I'd like to avoid. I'm not changing anything before (and including) the cat at this point. When I do, maybe I'll consider something with a bung, but for now, I'd like to use the stock parts, which limits the install to the downpipe.

LaXGSR · Aug 20, 2009, 10:55 AM

Another option would be to replace the front stock o2 with the wideband, and use the narrowband simulator output (assuming it has one) to go into the ECU. The wideband would then serve to replace both the stock narrowband as well as give you wideband o2 logging.

blk-majik · Aug 20, 2009, 11:11 AM

It's an LC-1... first time I've owned one, so I'm learning as I go. It has two analog outputs, both of which are programmable and one of which is setup for narrow band simulation from the factory.

Should the LC-1 fit the stock narrow band bung, or would I have to drill it out and weld the LC-1 bung?

Should the default simulation value ranges be compatible with the what the X ecu expects, or does the LC-1 need reprogrammed first?

LaXGSR · Aug 20, 2009, 11:14 AM

Yes, the LC-1 threads perfectly into the stock front o2 sensor bung. I believe you have to program the LC-1 narrowband output to match the voltage range that the stock ECU expects. This also will allow you to optionally have the LC-1 trick the ECU into running leaner than 14.7 AFR during closed loop (such as under light cruising). Someone else can probably chime in on how to do the wiring and setup, or check out the evo8/9 ecuflash subforum which should have more posts on this topic.

blk-majik · Aug 20, 2009, 11:26 AM

Thats great news! My welder won't be happy, as he was excited to try out his new MIG setup with argon gas on some stainless

Does anyone know the exact configurations for the LC-1 narrow band simulation to match up with the factory narrow band? I've seen some other threads showing how to wire the wideband into the ECU... I'll scour the VIII-IX forums for it again

Thanks LaXGSR!

coevolve · Aug 20, 2009, 11:58 AM

I'm interested in this setup as well. Please post your experiences if you have this setup!!!

stokEd · Aug 20, 2009, 05:18 PM

Quote:

Originally Posted by LaXGSR

Another option would be to replace the front stock o2 with the wideband, and use the narrowband simulator output (assuming it has one) to go into the ECU. The wideband would then serve to replace both the stock narrowband as well as give you wideband o2 logging.

Are you talking about the O2 simulator patch that's available for the Evo7-9 guys? If so, this unfortunately doesn't exist yet for the X.

Quote:

Originally Posted by blk-majik

Does anyone know the exact configurations for the LC-1 narrow band simulation to match up with the factory narrow band? I've seen some other threads showing how to wire the wideband into the ECU... I'll scour the VIII-IX forums for it again

Here's a thread I've started about doing something similar:
Logging Wideband AFR via Rear O2 ECU ADC Input

The link to the thread you're referring to is in the first post.

blk-majik · Aug 20, 2009, 05:40 PM

Yup, thats the one I was thinking of. I've obviously learned a lot in the past 2 weeks, because that thread makes sense now

I'm game for being a test mule

I'll PM you

tephra · Aug 20, 2009, 05:42 PM

Personally I would NOT replace the stock narrowband with the LC1... The LC1 is a PITA to get working properly, and is very finikey about power/grounds/etc - so it's not a good idea to rely on it for narrowband sim...

I installed my LC1 about 3" forwards (just after the slight bend) of the stock narrowband.

If I could do it again I would slightly rotate the sensor to the right (maybe 30degrees, when looking towards the front of the car) so that both sensors have a bit more clearance from each other.

stokEd · Aug 20, 2009, 05:57 PM

Quote:

Originally Posted by blk-majik

Yup, thats the one I was thinking of. I've obviously learned a lot in the past 2 weeks, because that thread makes sense now

I'm game for being a test mule

I'll PM you

Oh, the pleasure of finding things out.

It'll be a week or so before I'll have everything setup and ready to test, so you're the pioneer. Let us know what happens.

stokEd · Aug 20, 2009, 06:07 PM

Quote:

Originally Posted by tephra

Personally I would NOT replace the stock narrowband with the LC1... The LC1 is a PITA to get working properly, and is very finikey about power/grounds/etc - so it's not a good idea to rely on it for narrowband sim...

So is the best bet disabling and removing the Rear O2 and running the signal through it's ECU input?

Quote:

Originally Posted by tephra

I installed my LC1 about 3" forwards (just after the slight bend) of the stock narrowband.

If I could do it again I would slightly rotate the sensor to the right (maybe 30degrees, when looking towards the front of the car) so that both sensors have a bit more clearance from each other.

I always find little details like this helpful. Thanks.

tephra · Aug 20, 2009, 06:42 PM

Yes thats what I did.

When removing the stock front(down) pipe it might be easier to leave the narrowband IN.

I could NOT get a decent grip and rounded a few edges.

You can easily disconnect the sensor in the cabin (comes up under my clutch - RHD - so easier to LHD) and then push the sensor plug through the gromet.

Then just use a vice to grip the sensor and give the front(down) pipe a good wack with your hand to dislodge it.

I tried todo it quickly and cut the 02 wires - massive mistake, it was hell easy to push the connector through the chassis...

LaXGSR · Aug 20, 2009, 08:00 PM

This oxygen sensor socket is essential for getting the stock front o2 sensor off when still installed on the car:

http://www.harborfreight.com/cpi/cta...emnumber=97177

tephra, so you wouldn't trust the LC-1 as a narrowband simulator? How can I trust the LC-1 as a wideband then?