O2 sensor with 4 into 4 headers

[bil1024]

Is there a way around using the sensors ? I plan on running EFI but there is no bung for the sensor,thanks

[68GT500MAN]

You will need to add a bung. The EFI will need the sensor information to run properly.
Doug

[edwardb]

As Doug said they are required. Measuring Air-Fuel Ratio (AFR) via the O2 sensor is one the key elements of any modern feedback EFI system. Most won't function without it. Lots of threads, especially on the other forum, about the best location for various exhaust setups. Each EFI system should have recommendations about where best to install for their system. Typically the instructions describe the distance from the head, and will also give the "clocking" angle range. They have to point down, not up. It's usually best to get downstream of the 4-into-4 collector so you're measuring all four cylinders. But sometimes this isn't possible. Some engines (like the Coyote) give specific cylinders that should be used if only able to collect from one.

[Arvin]

Here is where I put mine. Technically, it is better the more cylinders you can read. However, I made a decision that I didn't want to see it. I went with the FAST EFI, came with a bung and O2 sensor. You can take it to a muffler shop but to somewhere that can do a good job on stainless welding. I had a machine shop weld and drill mine for $40. Car runs great!

43560

[DaleG]

You can find lots of info by using the "search" function and typing in O2 Sensors.

[frankeeski]

You can find lots of info by using the "search" function and typing in O2 Sensors.
Or, you can do exactly what you did and just ask the question. Some of us don't mind taking the time to answer your questions.

Here is my experience with O2 sensors. Using the stock Ford EFI the most important thing was to have the narrow band O2 sensors no more than 18" from the heads. The Ford sensors are heated but for some reason Ford recommends having them that distance from the heads and no more. I ran my stock 5.0 EFI with the sensor in one cylinder on each side for years and never had any drivability issues at all. Fast forward to now. I switched over to a Megasquirt/ Microsquirt system and had to add a single wide band O2 sensor to the passenger side collector of the side pipe. The Megasquirt system requires a broader sampling for as many cylinders as possible as it was described to me by the company I purchased the system from. So as stated by others in this thread, contact whomever you can regarding the system you are looking to install in your car. They can best tell you what the specs are.

[bil1024]

Thanks everyone!

[Bob Cowan]

What EFI system will you be using? Some of them (like Megasquirt) can run open loop, and don't need an O2 sensor. You're better off having it there, but not an absolute requirement.

[bil1024]

Using stock system

[Bob Cowan]

The stock system can be retuned to run in open loop only. But why would you?