Some lessons learned routing boost and wideband wiring/tubing

I'm in process of installing a wide band air fuel ratio and mechanical boost gauge in my 2005 Legacy GT Wagon. I wanted to share some lessons learned in routing the tubing and cable harness into from the engine bay into the vehicle.

 

*Pictures posted using tag%20with%20IMGUR%20hosting.%20Sometimes%20they%20do%20not%20show%20up%20in%20the%20post*

 

In my car there are two rubber grommets behind the intercooler. I removed my Grimspeed TMIC and the grommet on the passenger side is visible. After the fact, I didn't realize that there is a similar grommet on the driver's side that is behind some of that felt covering on the firewall.

https://i.imgur.com/1kvm1VU.jpg' alt='1kvm1VU.jpg'>

 

I ended up using the grommet closer to the passenger side. There is some thick padding just behind it. I used a knife, razor blade to cut into it and then pulled some out with needle nose pliers.

 

As the linked post stated, pushing a coat hanger through this hole in the firewall and towards the driver's side is the ticket. At first, I pushed a straightened coat hanger and was able to see it come out by the accelerator. I then taped my wideband cable to the remaining hanger with the intention of pulling the cable through. The coat hanger just pulled out from the tape.

 

I tried again, this time taping the wideband cable and boost line to the coat hanger and pushing it through. To my utter joy, both appeared down by the footwell near the accelerator

 

I was doing a cubby install. The next step was getting the boost line and wide band cable up into the cubby. Using a flexible grabber tool, I pushed it down from the cubby into the footwell. then grabbed the cable and pulled it through.

 

 

I'm not done yet, and shouldn't pat myself on the back. But I wanted to get this on here to help others who struggle with DIY like myself. It has taken me days literally to get to this point. Just going slow, stopping, thinking, trying, failing... I still need to do the wiring using 'add a circuits'. I still will need some professional help, as I can't get the plug off my Cobb downpipe to install the sensor. It is a 10mm hex head, and with my luck, I'm just going to end up stripping the head.

Edited September 16, 2019 by ashwinearl

Use some heat on it and use one of these and it generally will remove pretty much any rounded head bolt:

 

https://shop.advanceautoparts.com/p/irwin-bolt-out-with-case-394001/9010233-p?product_channel=local&store=1721&adtype=pla&product_channel=local&store_code=1721&gclid=CjwKCAjw5fzrBRASEiwAD2OSV-L4EqMYuED6UlDHUGUL8vJ2zKtXoLbZlAecpSq8_dPczldtdfy1BRoCFMgQAvD_BwE&gclsrc=aw.ds

I have the Cobb catted downpipe. The plug for an aftermarket wideband sensor is 10mm allen head cap bolt that is flush with the pipe.

http://www.subispeed.com/media/catalog/product/cache/1/image/473x473/85e4522595efc69f496374d01ef2bf13/5/2/524202-2.jpg

 

I'm worried about rounding out the inside of that allen head.

I smacked my bolt with an air gun, those heads are pretty sturdy. You might have to clean up the threads so get something like this for after. And put some anti seize for next time.

 

https://www.amazon.com/gp/product/B000XETMW0/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

and a new bolt something like this

 

https://www.amazon.com/gp/product/B01LDS0YRQ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

If you dont have some kind of impact wrench just use a 1/2 inch breaker bar. Don't be scared! And spray it down with some pb blaster or liquid wrench or something like that beforehand and give it time.

For some strange reason the plug for the aftermarket wideband is larger than a 10mm allen, was going to pick up a 12mm today as i am working doing this myself.

 

What are you using to hold your gauges?

 

I am using the Cubby Pod. The piece is in an L-shape. I installed it backwards at first with the lower L facing back. It is supposed to face forward.

 

I also broke one of the tabs that the Torx screws go into on the cubby.

Edited September 16, 2019 by ashwinearl

I smacked my bolt with an air gun

 

I have an Earthquake impact gun that I tried. I didn't have the air at highest pressure though. I think the head on the Allen socket isn't the best quality and might not be fitting tight enough. It just seemed to be rounding out the hole

 

Also my Allen socket is 3/8" and my breaker bar is 1/2" so there was the allen socket, a small extension to miss the heat shield on the turbo, and an adapter from 3/8" to 1/2" then the breaker bar. I think all those pieces where flexing and rotating and not getting the torque to the cap bolt.

 

Also I need to grind the head of the Allen socket totally flat so it sits in the pocket nicer. I have a nice 2x72 belt grinder.

Edited September 16, 2019 by ashwinearl

make sure the allen socket goes in about a 1/4". Its easier to get out with the downpipe removed. I sprayed pb blaster on the inside of the bung as well and let it sit for several hours.