[some_other_dave]

Sounds like you're starting to get it sorted out, good for you!! The workshop manual should help quite a bit. It may make sense to see if any of your buddies like to work on cars; they can help read the diagrams and lend a "calibrated ear" and eye to check stuff.

Originally Posted by AaronMartinSole

Watched a short video of the PCV Postive Crankcase Ventilation system. I think a clogged PCV can cause high NOx readings, but I have no idea ...
So do I need to clean out the breather box? Is this part of the recommended and necessary maintenance?

EGR takes exhaust and pushes it back into the intake. Exhaust doesn't have (hardly) anything in it that can burn, so it mostly acts as space filler. As mentioned in one of your later notes, it helps bring combustion temperatures down which reduces NOx formation.

PCV takes air (which has O2 in it which does contribute to combustion) from the crankcase that has oil spray and vapor in it. It separates out (much of) the oil from the air, and feeds the "dirty" air into the intake, where the oil gets burned in small amounts. That helps keep things cleaner, and helps reduce the pressure inside the "bottom end" of the motor, leading to fewer oil leaks and other problems.

If the PCV system started out clean (and it probably did), then it's not a bad thing to un-clog it and clean it up. It probably won't help your NOx emissions appreciably.

Also I just changed my manual transmission fluid using AMSOIL Synchromesh or something. ... I filled it with the car on jack stands. Someone recommended that I let the car down, then fill it. How do I know it has the right amount without a dipstick?

I know that in the older Hondas, the factory manual called specifically for 10W30 or 10W40 engine oil to be used in the transmission. Some current manual transmission oils are actually too thin and can allow damage to occur inside the transmission. I do not know if the oil you used is one of those, but it's worth looking in the manual to see what they have to say about recommended fluids. If motor oil is specified, I would use that--it's cheap and is the "right stuff", after all.

If you fill the transmission with only the nose up in the air, you will not get enough oil in there. I know this from my car; I killed two transmissions over the course of 100,000 miles by chronically under-filling them.

There are two plugs on the transmission, a drain plug and a fill plug. The fill plug was hard to reach in my car; I got a 17/19mm box-end wrench specifically for that, and it was still sometimes difficult to loosen. Always remove the fill plug first, because if it gets stuck you can still drive the car. Removing the drain plug first means there's nothing in the trans if the fill plug sticks.

You fill the transmission with the car level until the fluid is level with the bottom of the fill hole. So basically until the fluid comes out as you put it in, or until you can reach in with a finger and feel the fluid level with the bottom of the hole. If the front of the car is tilted up, the fluid level toward the rear of the transmission (where the fill hole was in my car, probably in yours also) shows higher than the actual level. That's why you want the car level.

5.) I'm going to check for vacuum leaks? (no idea how)

That's always an interesting question. You can do stuff like have the car idling, then spray WD-40 at the end of a suspect hose. If the idle changes, it is likely because some of the WD-40 got sucked in, so that end of that hose is probably leaking.

6.) Check for a dirty MAF and clean it. (Car only has MAP - Manifold Absolute Pressure. Still researching.)

No MAF on those cars. A MAF is used in many cars to tell the engine how much air is going in, so it knows how much fuel to spray. Older injected Hondas use the pressure in the manifold (measured by the MAP sensor) to guesstimate the air going in, so they use MAP instead of MAF.

7.) Check throttle bodies.
8.) Check fuel injectors.
9.) Check air regulator or IAC.
10.) Replace fuel filter.
11.) Valve adjustment.
12.) Check for exhaust system backpressure.

I have no idea what these things are, what they do, or where they are.

The fuel injectors are what spray fuel onto the backs of the intake valves. They are on the back side of the engine up near the top. In between the valve cover (the thing the spark plug wires go to) and the manifold (the thing that says PGMFI on it) you should see the fuel rail. The injectors are sandwiched between the fuel rail and the cylinder head. I'm not sure how I'd check them, frankly. Maybe send them out--but then you can't drive the car while they're out.

The IAC helps control the idle RPMs. On my car, it was on the back of the manifold. It had an electrical connector and a couple of vacuum hoses hooked up to it. It had clogged up, so I was able to remove it from the manifold (space is tight!) and clean it out with brake cleaner, then put it back on.

The fuel filter on my car was a fat cylinder on the firewall to the left and back of the engine. There were two hoses that bolted up to it; one hose led to the fuel rail (see fuel injectors above). Replacing it was a bit of a chore; there are flats on top of the filter for you to use a big wrench to hold it steady while you loosen and tighten the bolts for the hoses. The hoses have specific sealing washers that must be replaced, so have those on hand as well if you try this. It was a real struggle to break the bolts loose on mine.

The valves are inside the valve cover. There is a specified clearance between the things that push on them and the end of the valve. That is measured with "feeler gauges", which are strips of metal with very very specific thicknesses. There is also some "feel" so you can tell if the gap is too loose or too tight; the first time I tried on my Accord I set everything up very loosely and the car would hardly run. That's where it is handy to have a buddy who can stop by and check your work.

The exhaust system is everything from where the header bolts up to the engine (that's the four pipes coming out the front side of the engine) all the way back to the tailpipe.

One interesting thing to add is the speedometer on this car is very erratic jumping everywhere. If I remember right it seems to work okay over 40mph.

Could be a cable that is going bad.



Good luck with the car!

-soD