Wideband O2 sensor location help needed

[Curby]

OK, I just bought the EZ EFI system for my 1972 Vette. The car has a GM ZZ454 engine with the Hooker Super Comp side pipes and headers. The header collector is outside the frame rails (See attached photos).

The car was quite dirty in these pictures.


I want to put the O2 sensor in the collector.

I have seen guys mount them in the top of the collector, but then I would have to drill and weld the bung on top of my ceramic coated pipes.

I could mount it in the side, but it would be pointing down, and could collect condensate.

What would be wrong with welding the bung in the #7 pipe? I know it would no longer be an average, but isn't #7 one that is typically lean?

Thanks for the help.

[Curby]

I don't have enough posts to add the pictures.

[Curby]

I think this will get me to 10.

[Curby]

Here are the pictures

[rich22]

Nice Vette! I'm driving a 71 myself.

I think the problem you might run into by putting the o2 sensor on a single cylinder is that the reading would bounce around - especially at idle. Depending on what part of the combustion event was going on, it may read incredibly lean. By having it in the collector, you at least get to read cumulative result of 4 cylinders at once, with the different parts of the combustion cycle happening on different cylinders.

I have seen someone wire their o2 sensor through the fender vent and out to the collector on a Hooker sidepipe Corvette.

BTW, it is super important that you run a power wire and a ground wire straight back to the battery on the Corvette, on its own wire. I had all sorts of issues until I went back and did it right. I'd also recommend straight wiring the hand held computers power to the battery - using my cigarette lighter plug caused problems with the system, a bad ground I suppose. Can't trust any ground on a Corvette for this system, straight to the battery.

[Curby]

Thanks, Rich. I will run to the battery for sure. I have my MSD and fuel pump run straight there now.

I was looking at cutting out and welding in a 2.5" steel tube into the driver's side frame rail and welding the bung on the inside of the collector so it won't be seen or exposed to direct rain. If this is possible, I will do this. Otherwise, I will just weld it in the top of the collector like you have seen.

I was afraid that a single cylinder reading would be very unstable myself.

I just hate grinding off the ceramic coating and welding the bung on the top.

[bluzman2004]

You could hole saw a hole big enough in the frame rail for the O2 sensor to go through and install a steel tube through the frame and weld both sides. You could use a O2 sensor socket to install it. However, I've installed mine and didn't have to do that much. You won't be able to get the perfect suggested angle on the O2 sensor, but it will work. Mine has been in for a 1 1/2 years now. I drilled a hole and installed my bung in the collector at an angle that puts the O2 sensor almost touching the frame. The O2 sensor is pointing downwards slightly. Make sure you are not drilling into the part of the collector that has the side tube inside. When you weld the bung in, paint the welded area lightly with anti-seize. It won't burn away and will keep the weld from rusting. If it is welded correctly it will look perfectly fine. I will try to get a picture of it if I can.

Here's my junk... just a little EZefi on a small block.

[Curby]

I was thinking of trying that, but my headers are so high I can't get a good angle at all. The O2 sensor will be the lowest point of my car, and susceptible to speed bumps.

Love your set-up. That looks like a nitrous plate under your EFI.

[bluzman2004]

Hmmm, I'll try to take a picture of mine and you can see what it looks like. I havn't hit anything with it yet and I have speed bumps all through my housing division. I have seen these side pipes all seem to fit differently on different Corvettes.
It could possibly be 2 nitrous plates...

[bluzman2004]

Here are a couple of pics of my O2 sensor placement.