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I'm hoping others have had success with the location of the O2 sensor in the aftermarket header style side pipe collector for a EFI set-up.
I've searched the forum with little success on the issue I have run into here.
First of all, I know some will recommend that I do not use side pipes for flow, or other reasons, but I am committed to having them on my car.
Anyway, I have Stainless Steel Hooker Competition Headers going on my 73 Vette resto-mod with a 383 stroker I am building. I am using the Holley Sniper EFI for my fuel supply. Holley recommends placing the O2 sensor 6 inches past where all header tubes converge. That leaves me with a very small 2-3" area in which the O2 sensor can be mounted. Also, the frame is above 2/3rds of the 4" collector, so unless I have it showing, or drill a hole in the frame, I would have to mount it on the lower 1/3rd of the collector, and either weld a bung in on a 10 deg. down angle, which would make me have to either notch the collector, and have the sensor near the bottom inside of the tube, or have the 02 sensor mounted in a inverted, (coming from the bottom up into the collector, which Holley says will cause moisture to ruin the sender prematurely.)
Has anyone done these either of these options with success, or had any other ideas that worked. I know I may have blathered on here a bit, but I want to know how others have tackled this issue. I look forward to your advice.
I mounted mine exactly as you describe. Inside on the collector as close to the frame as practical. Results in a slight angle downward ward. No problem at all. I recently added a second WB02 just to optimize the total engine since I have the Dominator EFI.
Doesn't mounting the O2 sensor with a downward angle cause condensation build up to accumulate there and cause rust? Plus faulty readings. Every other comment on where to install sensor says to have at least a slight upward position.
Inquiring minds want to know.
Thanks
I mounted mine exactly as you describe. Inside on the collector as close to the frame as practical. Results in a slight angle downward ward. No problem at all. I recently added a second WB02 just to optimize the total engine since I have the Dominator EFI.
Doesn't mounting the O2 sensor with a downward angle cause condensation build up to accumulate there and cause rust? Plus faulty readings. Every other comment on where to install sensor says to have at least a slight upward position.
Inquiring minds want to know.
Thanks
I think you are just saying the same thing a different way if I understand you correctly.
The tip is downwards at a slight angle according to what Holley has stated, the outside connections upwards towards the frame. That's why I have been so concerned. There isn't much pipe to work with because the frame is in the way.
That is exactly where I have mine and probably every other C3 also. The instructions are not for corvettes but are for the optimal position of the sensor.
In a C3 vette you dont have that luxury. Pre mount the header and mark the spot that it is close to the bottom side of the frame, but not against the frame.
take off the header and drill the hole a little larger then the threaded hole in the bung, then weld on the bung.
I think you are just saying the same thing a different way if I understand you correctly.
The tip is downwards at a slight angle according to what Holley has stated, the outside connections upwards towards the frame. That's why I have been so concerned. There isn't much pipe to work with because the frame is in the way.
I understand now.
As you and others pointed out, it's not easy with our cars.
I wanted to post a picture for future people who have the same issue I and some of you here have had. Just finished up this mod to my right side pipe collector. 6" from merge. After posting this, with your comments, I got the confidence to do it to my new side pipes. I want to give special thanks to my brother in-law who tig welded all the stainless steel, & helped me. Turned out exactly how I measured it and no clearance issues. I can even get a socket on it to remove it.
You can just get a thick bung and then cut/shape it to fit against the tube giving the right O2 angle without building in a pocket like that. There are pictures here from others who have done it.
You can just get a thick bung and then cut/shape it to fit against the tube giving the right O2 angle without building in a pocket like that. There are pictures here from others who have done it.
Yes,
but #1 , I didn't want it to not stick out into the pipe enough that it didn't get a good reading.
#2, by indenting it, I had it higher in the pipe.
#3, I didn't have to worry about it hitting the frame.
That's why I decided to do it the way I did, and also I couldn't find any pictures of anybody's mods doing this. In fact, I searched and started this thread because I couldn't find any information. Holley, /Hooker had no idea what to tell me.
I know I missed your thread earlier so it's too late now, but here's a thread with pictures showing how to angle cut the bung to keep the sensor level. I know this one isn't quite level, but it shows the basic idea. Cut more off the top of the bung and it'll level out the sensor plus put it further into the pipe.
I know I missed your thread earlier so it's too late now, but here's a thread with pictures showing how to angle cut the bung to keep the sensor level. I know this one isn't quite level, but it shows the basic idea. Cut more off the top of the bung and it'll level out the sensor plus put it further into the pipe.
That's great, but on side pipe headers, it is a much harder endeavor because of the frame, and muffler/ pipe position gives you little to no room for much. That's why I sunk the bing into the collector. I will post more pictures later
I applaud all the great work you guys have done here, but personally I think your poll vaulting over mouse turds. For what its worth, I have mounted my ntk WBO2 on my two different BB cars in the collector portion of the Hooker header just forward of where the side pipe slides on. I have it centered in the pipe and angled down approx. in the 4 o'clock position looking forward to clear the frame. It has worked flawlessly on both the Holley and Accel Gen 7 setups for 15 years now.
I just went with it as close to the frame as possible. it's definitely not pointing down as recommended but I just figured if and when it starts giving me issues I'll just replace it . so far so good!! ZZ5 sniper system .
10-23-2018, 05:55 PM
EFI oxygen sensor location for side pipes
For what its worth, I have mounted my ntk WBO2 on my two different BB cars in the collector portion of the Hooker header just forward of where the side pipe slides on. I have it centered in the pipe and angled down approx. in the 4 o'clock position looking forward to clear the frame. It has worked flawlessly on both the Holley and Accel Gen 7 setups for 15 years now.
