o2 Sensor on only one set of cylinders?

[uflnuceng]

This is kinda exhaust/kinda electrical so I thought just put it in General Technical.

Im doing something funky with my exhaust for my turbo setup and will be needing to run a long amount of my exhaust back without any crossovers (i.e. no x-pipes/resonators/etc.).

Im going to have a custom ECU (Autronic SMC) which i will be able to program, but I was wondering if there is going to be a problem having the O2 sensor detecting only one set of cylinders (i.e. the front 3 or the rear 3). Im sure the stock ECU would have a shit over this, but I know people who run their engines without O2 sensors at all so I know the engine will run without it. I just want to make sure I understand the whole O2 sensor thing, especially with me running boost.

Thanks
Jared

[rs4pro3]

I put it on 4,5,6 and 6 on the M30 didn't notice any problems.

[uflnuceng]

Thanks Ely... you come to the rescue yet again... :up:

What were you doing with your exhaust that you had the O2 sensor in only one pipe?

[rs4pro3]

E28 535is Dual downpipes(had the O2 at the Cat), Then dual 1.75" cats, then dual pipes to the stock E30 connection to the Rear muffler, and I had flanges welded so any 325i stock or aftermarket muffler can be bolted straight on. The pipes don't join anywhere untill the Muffler. And it sounded Awsum!!!!!!!! Man I miss it

[uflnuceng]

Yeah... that damn cat gets in the way of the heat shielding brace... I guess I will put that up on the exhaust part of my M30 writeup. Been getting a lot of positive feedback on that site :D

What kind of cat's did you use? Cost? Brand name? I need to get a couple myself for this project. I'll have to fill you in on it through PM as it is super top secret ;)

[rs4pro3]

Ebay Universal ones $40 each. Wasn't going to run cats but my town started emission testing so figured I better put some in then then in about 7 months down the road when it would need tested.(If I had known now the engine wouldn't of made it to that date )

http://cgi.ebay.com/ebaymotors/1-75-1-3-4-Catco-Catalytic-Cat-Converter-NEW_W0QQitemZ7931889017QQcategoryZ33629QQssPageNameZWD1VQQrdZ1QQcmdZViewItem

[kowalski]

Ebay Universal ones $40 each. Wasn't going to run cats but my town started emission testing so figured I better put some in then then in about 7 months down the road when it would need tested.(If I had known now the engine wouldn't of made it to that date )
http://cgi.ebay.com/ebaymotors/1-75-...QQcmdZViewItem

im guessing it blew up? as for the O2 sensors the only problem with running on 1 side is it will only be detecting half of your exhaust which isn't really a big deal... unless for a freakish reason the other injectors start to fail which you would notice because of a power drop... why dont you just run the O2 sensor back to your cross over? then you can have all the cylinders?

[rs4pro3]

Rings gave out on it.

[kowalski]

ahh well that sucks balls... not going to rebuild it?

[rs4pro3]

Don't have the funds and the chassis it was in had a previosley bent frame rail so I parted out the car.

[kowalski]

ahh well that sucks, and such is life:(