Just went out to replace the tail light bulb. I bought Sylvania 2057LL after consulting the auto parts book at Kragen. Turns out its the wrong bulb even though that's what it recommends. The 2057 has two silver domes at the bottom whereas my car's bulbs have 1 silver dome. Also I switched out the bulb from the working tail light to the nonworking one and the tail light still didn't light up. This means the socket for the bulb is broken or somewhere down the line its broken. So I guess I gotta get a voltmeter and checking if any wires are loose, or worse case, connect wires from the working tail light to the non working one.

What is the tenth digit in your VIN number? That will tell us the year of manufacture.

If there are 5 wires in the O2 and the registration says it's a 94 model, it can't be a CA spec VX.

Sounds like you'll need to buy the 5 wire replacement.

The Brake/Tail lights (the outer ones) take an 1157 as well as the front turn signals.

The inner tail lights take an 1156 bulb as well as the reverse lights.

Here's your fix for the worn driver's door lock: https://honda-tech.com/showthread.php?t=2237857

I just went to mechanic today
The compression in cylinders 1,2,3,4 in that order is: 115, 110, 115, 120 psi
The mechanic said there was nothing wrong and those were the normal compression values. They are within 10% of each other so I guess it is fine.
I also asked about the smoke coming out the tailpipe. He said he didn't see anything out of the ordinary. Also I asked about starting the car where it cranks a while to start. He said it started up fine when they tried it.
The only problem was the CEL code 48 which indicated I needed new Federal O2 sensor. He said it was $150 for the O2 sensor and $90 for labor. I said I'd buy the part and come back for labor. Or maybe I can do it myself.

So I'm pretty happy my car isn't broken. But can someone please tell me those compression values are good? Also I looked it up and the compression ratio for the d15z1 is 9.3:1. What does the ratio mean?

Regarding the car cranking a while before it starts: Try turning the key to "On" for a couple seconds before turning it to "Start". Listen for the fuel pump (probably a faint whirr sound), and once the fuel pump stops, then try cranking it. If it fires immediately when you do that, you are losing fuel pressure while parked.

(That's assuming that the VX has the same fuel system behavior as cars I'm used to.)

That could be related to your gas cap hissing at you. While that can certainly be normal, it can also mean that your fuel pump's check valve is allowing pressure to leak through the fuel pump back into the tank.

the compression ratio is the ratio of volume from the pistons top dead center point and it's bottom dead center point.

for example, with the piston all the way down, the cumbustion chaimber may have a volume of 0.25 liters. with the piston all the way up, the cumbustion caimber may have a volume of 0.025 liters. this would make you have a compression ratio of 10:1. this is just an example I made up.

the compression ratio has nothing to do with compression testing your motor. basically they are seeing if the rings are still good and it will hold pressure.

(disclaimer: not a mechanic so take it for what it's worth)

theholycow, I noticed the link to the $99 5wire O2 sensor in your sig. Does that O2 sensor work with the 1994 Civic VX federal model? I checked the link and it says upstream, which means in the exhaust manifold.
Is that where mine goes in?
I checked on Ebay and they sell for around $200 which is too pricey for me.

I'm not personally experienced with it, but plenty of people have bought it and you can find success stories on this site. Nobody has reported failure. I'm pretty sure it's specifically for the federal model, as IIRC the Cali model doesn't require the expensive wideband sensor.

It's the only known place to get the sensor for less than $200.

It is good that your compression psi numbers are within 10% of each other.

In my opinion, those numbers are a little lower than I get when I compression test my Honda 1.3 liter (I average around 180 psi, but it has 10:1 compression ratio) but there are so many variables (starter gearing/cranking speed, was the engine hot or cold, did the mechanic hold the throttle valve open, etc.).

A good test of the condition of the piston rings is as follows:

Bad or stuck oil control rings- blows lots of blue smoke at high rpms and at high loads (such as doing a 0-60)

Bad compression rings- open the oil fill cap while the engine is idling. An older engine (100K+ miles) will have some air and oil splatter blowing up out of the valve cover.

An engine with lots of combustion gasses leaking past the compression rings will feel like there is a hair dryer blowing up out of the valve cover and there will be oil mist flying everywhere. Also, the engine oil will get black within a few hundred miles after an oil change because of all of the combustion gasses contaminating it.

Failing valve stem seals= A puff of blue smoke at start up or a puff of blue smoke when taking off from a stop sign

Bad valve= a miss on one cylinder at idle and a low compression psi reading on that particular cylinder