I have a couple questions about the DC header for the Y8 motor. Since they are both D-Series, the header should bolt up fine to the A6 head? Also, is the 02 location the same as in a header designed for a A6? And last, will it bolt up to a stock exhaust system for a LX sedan or will components have to be changed around?

 

Yes it will bolt up to the A6 head no problem. But it does hang lower behind the oil pan as the +92 exhaust manifold slope down slightly. It's not that bad but it is lower.

As for the O2 sensor you should put a O2 bung up by the head like the stock A6 has. The y8 o2 sensor is located at the end by the cat since it has a heater. It would work OK in the Y8 location but I'd put it in the right place myself.

And I don't think that it would bolt up to the cat/exhaust, it should be close but you will have to some work on it.

 

Ok, the car isn't lowered yet so no problem there with it hanging lower until later. I did read that you could use a four-wire O2 sensor in the stock location and wire it to run off a 12V line that is on with the engine. How much work are we looking at attaching to stock exhaust; Is it something that is bolt on /off or chop and weld?

 

Even if it's lowered it's not that bad, I was just letting you know about it.
Yes if you wanted to you could use the new style heated O2 sensor.
I'm guessing (it's been so long since I've seen a stock exhaust) that the one of the flanges will have to be rotated for it to mate to the cat that's all.

 

Well thanks for the help, I'll let you know tomorrow how it looks after I pick it up.

 

I have y8 dc header on my dohc zc no problems.

 

Aren't the exhaust ports on a DOHC ZC a little different then the other D-Series heads? And what did you do with the O2 Sensor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dr_latino999 &raquo;</TD></TR><TR><TD CLASS="quote">Aren't the exhaust ports on a DOHC ZC a little different then the other D-Series heads? And what did you do with the O2 Sensor?</TD></TR></TABLE>

You can grind header ports its not a big deal. All the headers have various O2 locations you can mount the O2 anywhere its just a question of lentghening or shortening the wire(s).

 

Actually the ports on the dc sports y8 header were larger than the a6 manifold ports. Only one did not match up and it was pretty close. as for the o2. I cut the platic covering over the harness until there was enough slack to plug it in at bung. Someone wrote they thought you should move the o2? I disagree. Wouldn't you get a better reading with mewer bung location instead of what one cylinder reads(stock location). I think honda knows what there doing.

 

Ok, so it turns out it was a 4-1 design, pretty spiffy, but it's a one-piece so on installation. The O2 Port is all the way in the rear, and I have decided to run a four wire sensor at the bottom. The reason Honda moved the ports farther down the manifolds is that the newer models are heated. OBD-0 02 sensors are unheated so they must be placed closer to the head. Also, I am in the market for a new O2 sensor anyway due to the fact mine works randomly, and I don't want to worry about welding on anything to this. Eying the flange on the stock one, I should be able to just bolt it on for now and call it a day. The only thing I will have to check is the length of the whole Header, it may extend past the stock pipes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4potnick &raquo;</TD></TR><TR><TD CLASS="quote">... Someone wrote they thought you should move the o2? I disagree. Wouldn't you get a better reading with mewer bung location instead of what one cylinder reads(stock location). I think honda knows what there doing. </TD></TR></TABLE>

but on the a6 the sensor location was on the primaries tube not the collector. The ECU must also compensate for the difference in readings from one location to the next. IMO, this would cause the motor to get the incorrect readings.