Oxygen Sensor Loactions

[haroldd1963]

I ordered our Roadster Basic kit the other day.

Wanting to get all my ducks in a row.

I ordered it with the long tube ceramic coated headers.

When I placed my order, Jason told me the best place to locate the oxygen sensor would be in one of the primary pipes.

Do any of you have pictures of where you positioned the sensor in the header?

Also, where did you get your O2 sensor bungs?

One more question. Jason said to drill the hole for the bung and to gring the ceramic coating off around the hole to clean it up for welding....is there a ceramic coating in a spray can or brush on application available?

Thanks,
Harold

[dhungerf]

Take a look at my blog. Last season I did the 4 into 4 header upgrade and the O2 sensor location is shown. There will Be many other opinions, but this location works well for me.

http://ffr5355.wordpress.com/ffr-5355-factory-five-cobra/4-into-4-headers-side-pipe-modifications/

Hope this helps.

[Blue MK3]

Your question relates to why I didn't convert from a carb to EFI. All the EFI units I looked at said the O2 sensor must be located above the horizontal, that is between 9:00 am and 3:00 pm. My pipes are close enough to the body that there is no place to hide it coming out on the inside. Rather than having it sticking up in plain view with a wire leading to it, the alternative was to install it under the hood in one of the header tubes, well before the collection point. But that would be measuring only one cylinder, which doesn't seem to give an adequate picture of what's going on. So I changed out my worn out, internally corroded Holley for a Quick Fuel carb (without a choke). It's about as close to FI as I can imagine. One pump of the gas pedal, start it up, and it's idling at 1000. I drive it away as soon as I get my five-point belts hooked up. And this with a fairly aggressive cam in a 347 stroker. If you read this and the other forum, you'll see numerous threads about the difficulty of setting EFI systems up. Despite the videos from the vendors, they're not always plug and play systems. That said, if you're in the initial planning process and still want go with EFI, consider setting the side-pipes far enough from the body so you can install the sensor at the horizontal with room to clear the body. That might mean taking a VERY WIDE step when exiting the car to avoid a burn on the leg. Just my $0.02.

[skullandbones]

I have found that placing the bungs in the side pipes works fine. I'm not the only one to do it. I would not have tried it if I didn't think it would work. This is not a stock OEM installation anyway. So you have to use some innovative techniques (American ingenuity). My O2 sensors are at about 8 oclock. I plan to take them out and check them regularly which I have already done once. The stock PCM seems to like what I did. I used an after market EFI harness from Summit and was able to easily lenghten and solder the extensions (be sure to solder). My sensors clear pretty well. They are app 5.75 inches from the ground and app .75 inches from the body edge. I don't think I could have gotten the angle much better than that. I believe the trouble I went to will create a better reading for the PCM. I will verify the data more scientifically (A/F) when I start tuning. Good luck. WEK

[bill3422]

I ordered our Roadster Basic kit the other day.

Wanting to get all my ducks in a row.

I ordered it with the long tube ceramic coated headers.

When I placed my order, Jason told me the best place to locate the oxygen sensor would be in one of the primary pipes.

Do any of you have pictures of where you positioned the sensor in the header?

Also, where did you get your O2 sensor bungs?

One more question. Jason said to drill the hole for the bung and to gring the ceramic coating off around the hole to clean it up for welding....is there a ceramic coating in a spray can or brush on application available?

Thanks,
Harold

I have a 302/347 stroker. I use a Mass-Flo EFI and the instructions with it basically came with the same instruction. They say to position the sensor with in 12" - 18" from the exhaust port on the header. It would be best if it were in a collector of all 4 cylinders from that side of the engine, but the distance from the head was more important, so one tube would have to do.

The next instruction was to choose a location where condensation would not be an issue. I read that to mean to mount on the side or top of the tube since condensation would be more apt to be running on the bottom of the tube. I picked a spot that met all the criteria and was easy to get to. The bungs I used came with the Mass-Flo unit but I know can be ordered separately from them as well.

If you are doing the work yourself I would recommend getting a "thread chaser" to touch them up when completed welding. http://www.amazon.com/gp/product/B000XETMW0/ref=oh_details_o03_s01_i00?ie=UTF8&psc=1

http://i1302.photobucket.com/albums/ag139/bill3422/Cobra%20Build/IMG_0697_zps4253d1cc.jpg (http://s1302.photobucket.com/user/bill3422/media/Cobra%20Build/IMG_0697_zps4253d1cc.jpg.html)
http://i1302.photobucket.com/albums/ag139/bill3422/Cobra%20Build/IMG_0698_zps400e4c85.jpg (http://s1302.photobucket.com/user/bill3422/media/Cobra%20Build/IMG_0698_zps400e4c85.jpg.html)
http://i1302.photobucket.com/albums/ag139/bill3422/Cobra%20Build/IMG_0701_zps08f55ab5.jpg (http://s1302.photobucket.com/user/bill3422/media/Cobra%20Build/IMG_0701_zps08f55ab5.jpg.html)
http://i1302.photobucket.com/albums/ag139/bill3422/Cobra%20Build/FA129A88-14FE-4029-B7D3-3D717E88DF67-859-000000AFFE412760_zps4a93608e.jpg (http://s1302.photobucket.com/user/bill3422/media/Cobra%20Build/FA129A88-14FE-4029-B7D3-3D717E88DF67-859-000000AFFE412760_zps4a93608e.jpg.html)

[haroldd1963]

Thanks for the suggestions!

[GJerry]

I got the bungs from Factory Five. I used the silver colored never seize to coat the weld areas of the bungs on my ceramic coated headers and have never had a problem with it and have never had to replace it in over 6 years although I never drive my car in the rain.

[MPTech]

I mounted my O2's on the upper single pipes and the car & computer run great.
When you get ready to mount locate them; measure, then measure again, then measure one more time! I WISH HAD!
Also some really good information here too:
Kicking myself, should have measured BETTER!! please help (http://www.ffcars.com/forums/17-factory-five-roadsters/299202-kicking-myself-should-have-measured-better-please-help.html)

I had to remove and re-weld one of the bungs and do some clearancing on the other. It was fixable but could have easily been avoided.

Here's some bung information that may also be helpful.
Time to have my O2 bungs welded, need some advice (http://www.ffcars.com/forums/17-factory-five-roadsters/296284-time-have-my-o2-bungs-welded-need-some-advice.html)

Good luck!