Ga16de header and cat relocation

[vegas2.0S]

I Have a B14 200sx. The exhaust manifold on this engine stinks. I want to install headers but doing so will eliminate the CAT. I also want it to be street legal so I'm thinking of moving the Cat to where the first muffler is located, eliminating that muffler and installing a performance muffler in the rear. I'm thinking this should free up a good amount of back pressure.

1) Is there any problems that this would create that I should anticipate? 2)The major problem I have is I don't know anything about O2 Sensors where should they be installed. Should I install the O2 sensors, in the exact same spots (i.e. right at the exhaust manifold) or do I just have to get one in front of the CAT and one in back of it?

Any help would be appreciated

[spdfreak200]

ur best bet is to drill a hole where the O2 sensor will reach and go buy a bung or a big enough nut that will fit the sensor and weld it to the exaust that way it can still read out and not throw a code...i blew the O2 sensor in my cat out like 2 years ago and my light isnt on at the moment...i just welded up the hole and zip tied it up hahahaha

hope that works for ya!

[vegas2.0S]

So I looked at some of the tech manuels pdfs that are on NICO. I found that the First O2 sensor is what gives the ECM it's info for the air fuel mixture the 2nd one does have to be behind the CAT for what I'm not sure. The header I found for the GA16DE has a port for a O2 sensor. So I just need to put a port in somwhere behind the CAT which I'll get done when I move the CAT to the new location. I think that will work from what I read last night. I still would like to find somthing that tells you where the best placment for O2 sensors is.

[nametakennow]

The first sensor is for the ECU. The second is for emissions. It is behind the precat, which is in the exhaust manifold. Putting on a header removes the aforementioned precat (smaller, faster-acting cat converter designed to reduce emissions on cold starts), so moving the 2nd O2 sensor behind the cat in the middle of the exhaust stream will avoid the code by tricking the sensor. There are other methods as well. Check out the Common Issues thread in the Table of Contents for a fuller explanation of how to avoid the light. That thread may say B15, but this info is for any OBDII car.

[vegas2.0S]

don't think I have a second CAT. From what I was reading I forget where the b14s only have two CATs on Cali. Emissions rated models. But, I assumed that I didn't have one of those. I was thinking I have a resonator. but I haven' t really taken a good look. So thanks for the Idea nametakennow. If I don't have to replace the resonator that would save me some trouble. Let me ask you this though, if I do have a resonator should I get just any universal CAT (ie: Magnaflow) or should I replace it with something more like the one I would be taking of the exhaust manifold?

[nametakennow]

Agh, you're right, I forgot about that. We had another B14 owner ask about this awhile back.

If you remove the cat you'll need to use a spark plug defouler (instructions are in the same place I mentioned in my last post) or electronic "ghetto" sim to fool the ECU.

Alternatively, you can get a high-flow cat and stay legal while gaining hp.

Without a resonator the car sound buzzy and tinny. Make sure your exhaust has one.

[94 Sentra-XE]

i would just run no cat and just weld in the o2 sensor in a different spot