b20a ,o2 sensor

[b20a86lude]

well im gettin a custom header made . and it wont have a place for the 02 sensor. should i put it in the downpipe or the header. and would i need 2 or one.
guys with b20a wat o2s are u using

[2ndGenGuy]

If you're running the stock computer, you'll probably want to run whatever that has provisions for (1 or 2, I'm not sure, I think that depends on where the ECU came from, and emissions controls the car has). If you're running an aftermarket computer, you'll want one where the header joins down to one pipe. And it has to be before the cat. The closer to the engine, the better as the signal will be less delayed.

[carotman]

The number of O2 sensors will be dependent on which ECU you'll use. The engine doesn't need any O2 sensor in fact, it's the management system that will use it.

If you use a single O2, it needs to be able to "see" all the exhaust gases (from all the cyls). This means it needs to be on the single pipe part of the exhaust (usually the downpipe)

If you have 2 O2 sensors (PK2 ECU) it can be on the downpipe too but each sensor will be on it's own pipe.

So Assuming you have a 4-2-1 header:

Single O2: Install it on the "1" part of the downpipe
Dual O2: Install each sensor on the "2" part of the downpipe.

Is it clear?

[carotman]

Oops, I got ninjaed

[MessyHonda]

yeah obd1 ecus want the heated 02 sensors

[cygnus x-1]

One thing you might consider is getting a wide band O2 setup like the ones from Innovate Motorsports.

http://www.innovatemotorsports.com/products/lc1.php

The cool thing about these is that they have 2 fully programmable outputs. So you can set one output to read like a standard OEM type narrow band sensor, and the other output to read as a true wide band sensor for an external AFR gauge. Or if your ECU can handle a wide band signal you can program both outputs for wide band. They can also connect to a Laptop for data logging.

C|

[Ichiban]

Why does my factory B20A manifold put the 02 sensor where it reads 2 cyls only?

[2ndGenGuy]

Your manifold didn't have two O2 sensors on it?

[Ichiban]

Now I'm starting to wonder. It may have.

[carotman]

Nope, the B20A manifols is kinda "special"

It has a chamber where the O2 sensor goes. It can read the 4 cylinders.

[AccordB20A]

yes indeed i have seen its random and takes pulses from all 4 cylinders, All b20a have one oxy sensor, the other holes u may see are for EGR

[2ndGenGuy]

I'm gonna go look at mine again... The EGR is that big hunk of cast iron hanging off the side that's cast shut... I could swear mine had two O2 sensors, but I could be on crack.

[Ichiban]

Nope, the B20A manifols is kinda "special"

It has a chamber where the O2 sensor goes. It can read the 4 cylinders.

Oh it's "special", all right.

[mykwikcoupe]

short bus special. if your plans in the future are perfornace oriented you may consider upping to obd1 and using the heated O2 sensor. Theres tons of write ups on the board and I think none of us had issues with signal loss. If your going N/A only Id just put it beofre the bend above the fron crossmember. this way the factory eiring stays intact and you know you wont have clearance issues down the road. Since I am obd1 I placed it under the oil filter just after the hanger stay the bolts to the rear of the block. Theres a ton of room and the wiring was made to drop off just like the IACV sensor. It looks so much better than factory.

[AccordB20A]

thats where most OBD1 cars have it located also.