Hey guys. I have a EX 4-cyl engine in a 1995 LX 2-door 4-cyl body. It has the LX exhaust system.

I've been increasingly smelling gas in the exhaust and after having replaced the plugs, plug wires, dizzy rotor, and bleeding the cooling system, I realized that the oxygen sensor I had installed was for the LX (and was pretty worn).

Questions:

1. Should I have the LX oxygen sensor or the EX one?

2. Should I replace the LX exhaust manifold with the EX one?

3. How's your day going?

Thanks guys!

 

How did you get the V-TECH head to except the non V-TECH exhaust manifold?? Everything I've read on the V-TECH engine (basically the cylinder head) is the exhaust layout is different between them (EX) and the non V-TECH version (DX and LX), and it shouldn't swap. Add in the V-TECH head uses 2 down pipes from the manifold versus the single of the LX.

That said, which wiring and ECU did you use with the swap? Just asking, as that might determine which O2 sensor to use, although they might actually/probably are the same sensor (it's location might be what's different between them).

As far as how my day is going, it's going great. I fixed my 97 LX yesterday, and now it runs.

 

Well, the previous owner did the swap. I might be wrong, but I thought by looking at pictures that I had the wrong manifold. So I took some pictures and maybe those will help.

http://imgur.com/SRVb3li

https://i.imgur.com/YmKtVU7.jpg

And I'm using the LX wiring harness and the LX ECU. Oh and congrats on getting the car running!

 

Ok, you have the LX manifold on an EX head. What the PO did was remove the middle lower stud, so the manifold would bolt on.
What I'd do is go to RockAuto, and look up both O2 sensors, and see IF they are same part number. If they are, then it doesn't matter which you use. But, since everything else appears to have been kept LX, I'd probably use one for that engine and model.

 

NGK does have a different part number for the LX and EX. I have the LX sensor in currently and I think I'm just going to install the EX sensor and see how it works. Hopefully it solves my running rich problem.

Also, with that middle lower stud removed, could I still do a manifold swap if I found one at the junkyard or something?

 

You'd have to look at the plug of both O2 sensors and see if they are the same. I only say that, as you might find something different between the plugs, and that's why the PO used the LX sensor. That's one of the things I noticed on my own car when going thru the FSM, the plugs for the EX were different in some places, versus what I had (an LX).

If you get the right manifold and down pipe, you could just add the stud that was removed, and use the EX manifold. You'll need an EX exhaust gasket too.

 

Awesome, thanks! And that's good thinking because I have the LX wiring harness, so I don't know for sure if it will fit untill I try it.

I'll update this thread once the EX oxygen sensor arrives and again if I can manage to do a manifold swap. Thanks so much for your help.

 

That's why I suggested looking at Rock Auto's site. If you click on the "info" button, they show a picture of the sensor. Sometimes they'll give alternate views of the plug too, and you can compare the differences.

 

Oops I missed that, sorry. I just checked out Rock Auto and it does look like the plugs are different. Do you recommend splicing the old sensor and trying to plug it in?

 

Are you saying you changed the wiring on the plug of the O2 sensor you installed previously? Why? Was it because the car had an EX end on it, and you had already bought the LX O2 sensor? I'm not sure what you did previously when you changed the old one.

What ECU are you running? Is it an EX? Or LX? If it's an LX, then the V-TECH parts might not actually be working. But if the V-TECH is working, then the PO must have used an EX ECU and possibly the wiring (engine harnesses) too.

You could try splicing the old sensor plug in, and then maybe you can use something that just plugs in (like normal). Just make sure it matches whichever plug you get on the new O2 sensor.
Note; we did something like you're talking about on my son's 98 Civic when he added a header to it. The new header moved everything down and away by almost 2 feet, so we had to extend all of the wiring for both O2 sensors. It worked out fine, but it was a PIA to do in such a tight space. He installed a 4-2-1 header on it that was stainless steel. His next project was the rest of the exhaust got increased to 2.25 inch Id pipe (custom built out in my garage), along with a high flow cat. Most of this was done because his old exhaust manifold was cracked, and they wanted 500+ for a new one due to it having the catalitic conveter built into it.