Lack of power, hesitation, #1 miss firing

if you have spark at the plug on #2 then check the injector for voltage and ground you may have a bad injector or plugged or dirty injector. it could also be a vacuum leak at the intake were it meets the head at cyl#2.

It just can't do that. No way to shut down one side of an engine.
Misfires are caused by lack of fuel, spark, or compression. One of the three is missing. One whole side-that rules out spark. Coil pack design just won't affect one side of the engine. That leaves fuel or compression. Some multi-port injection systems are so-called "bank fired" -that is, one side or bank of the engine will pulse the injectors at the same time, first one bank, then the other. But in the early '90's, some cars came out with sequential fuel injection, which pulses the injectors individually, following the firing order of the cylinders, more precise fuel metering that way. I would have thought that an Avalon would be sequential injection, but you could check. Anyway, you need to check if the injectors are working on 2, 4, & 6. The power wire to all injector systems is a single wire that is spliced to each injector. Conceivably, the splice to that bank or side may have broken. With key on, every injector should have voltage at the injector connector. Only two wires to each injector- a power wire and a ground wire. If no power on 2, 4, or 6-that is probably it. (On bank fired injection, all three ground wires on each side splice together before the ground wire goes into the computer. With sequential, each injector ground wire goes to the computer separately.)
Beyond fuel, it is possible that the fuel/air mixture is being affected on only one side. If you have a noisy exhaust leak on that side, it could lean out the mixture.
Finally, low compression will cause a misfire. Possibly, a camshaft on that side is not in time. Only way to check is to do an engine compression test.

possibly wiring harness fault,sesor wheel installed backwards or an even fire/odd fire engine mismatched components

Hi, the first step I recommend is to check for spark. You can do this by starting the car and then carefully pulling up the boot to the #1 ignition wire at the coil. If sparks are jumping inside the boot, you have spark and the ignition system is working.

1. Ignition: If there is no spark, shut of the engine and use an ohmmeter to check the impedance of the coil. Take the boot off, and connect your ohmmeter from the coil terminal to the engine ground. The resistance should be around 10-20 kohms. If not, replace the coil. If yes, the problem is the ignition module under the coil.

Now, assuming you have spark (which I believe you do, because the coil runs 2 cylinders, and you only have one cylinder that is misfiring), the problem will be a lack of compression or a bad injector (or possibly the injector wiring).

Note: I will provide repair steps once the troubleshooting is complete and the problem identified.
Also, if you do not have a multimeter, you can get one for $10-20 at radio shack or even Walmart. It will save you money overall--or maybe you have a friend that you could borrow a meter from.

2. Injector: The next easiest test to run is to see if the injector solenoid is clicking. You can do this by holding a long screwdriver to the injector and hold the other end of the screwdriver to your ear. With the engine running, you should hear the injector clicking. If not, you have a bad injector or a wiring problem. To determine whether the problem is the injector or the wiring, pull the connector off the injector and measure the AC voltage in the connector with the engine running. The voltage should be 1-2 volts or similar to that voltage of any other injector connector.
If the voltage is good, but the injector is not clicking, replace the injector.

3. Valves/compression: the last possible reason for a misfire is a lack of compression. The intake valve must open to accept a fuel/air charge, and both valves must be closed for the cylinder to fire. Sometimes an exhaust valve will burn and not hold compression. A blown head gasket can also cause this problem. The test we use to check the valves is a compression test. You can borrow or purchase a compression tester if you get to this point. Remove a few of the spark plugs including the cylinder that is misfiring. Screw the compression tester into the spark plug hole and crank the engine for a few revolutions. Record the pressure on the gauge, release the pressure, and go on to the next cylinder. If the pressure is much lower on any cylinder as compared to the highest cylinder, the cylinder head will have to be removed to correct the issue.

Please let me know the results of your troubleshooting and feel free to ask questions as you go.

first do a cylinder compression test on engine to verify good engine compression this should be around 110psi to 175 psi check for vacuum leak, intake port for #6 cylindermay be leaking air, or also check coil for that cylinder, if wire and spark plug have already been changed, last replace fuel injector for that cylinder.

Could only be a few things. The coil #1, Fuel injector #1, Stuck intake or exhaust valve, or blown head gasket allowing coolant into cylinder #1. Use a spark tester to check the spark coming out of cylindr #1 if checks good then ohm test the injector when it is warm. Check other injectors to compare. Do a compression test on cylinder #1 and test other cylinders to compare. If cylinder is low compression suspect valves and or head gasket. If compression is low then het a leak down tester to test if a valve is broke or sticking. On your sable i would suspect injector or coil most likely.

check valve adjustment on #5, is cam lobe worn?

It could very well be a bad coil pack,or you have low compression in that cylinder.If the compression is good then go with the coil pack,if not you may need a head gasket or an intake manifold gasket.

Problem could be as simple as a vacuum leak around either of those cylinders. A vacuum leak can create a lean fuel mixure condition resulting in a miss fire. One thing to rememeber is that depending on the style of ignition in use. The opposing cylinder's spark plug and wires act as the return path for the unused voltage from the coils firing which is why you are having seemingly unrelated misfires. If either has a problem then the symptoms are shown in both cylinders.

First check plug and make sure the right plug for this vehicle,make sure that the heat rating for this plug is correct. Your problem could be a wrong heat rating plug been installed. Also make sure that the misfire is due to a bad plug and NOT a bad injector or injector wiring or uneven compression or even bad coil. Check injector wiring and make sure it not shorting or broken. To check injector pulse use a NOID light can be bought at almost any auto parts store like Auto-zone etc. Also compression can be checked with compression guage. A rule of thumb to go by is if any cylinder has more than 10 PSI in difference in compression there is a problem like a burnt valv etc. Here is a n example cyl# 1 170psi cyl#2 176 psi cyl#172psi cyl# 4 150 psi, there is a problem with cylinder # 4 and will cause a miss from cylinder #4. Good luck and thank for using FIX YA