Engine miss most common cause - 2002 Toyota Camry

Yes, there is a possibility the plugs could be causing the problem. Check the spark plugs ,One at a Time, to see what the electrode end inside the engine looks like. It would be a good idea to change them anyway. There are other reasons for a misfire. I have attached a link giving a list of other causes of misfires.
https://www.arnoldclark.com/newsroom/2502-the-most-common-causes-of-engine-misfires

Misfires and Their Causes
Ignition Misfire
An ignition system problem is one of the most common reasons for an engine to misfire. As the spark plugs, ignition cables, distributor cap and rotor, and ignition coil wear over time, their ability to transfer the needed spark to ignite the air/fuel mixture inside the combustion chambers becomes compromised. In the early stages, the spark will only be weaker and the actual misfire will be subtle. As the ignition components continue to wear, the misfire will intensify and the combustion process can be interrupted completely. This will cause a severe jerk or shock in the operation of the engine (the engine may even backfire through the air intake system, producing a loud "pop").
Lean MisfireThe lean misfire is another common reason for an engine "miss"-this is due to an imbalanced air/fuel ratio (too much air/too little fuel). Since an engine needs a richer (more fuel) mixture for a smooth idle, this problem may be more noticeable when the vehicle is idling. The lean misfire may decrease or disappear as the engine speed increases because the efficiency of the volumetric flow into the combustion chambers increases dramatically. This is one reason why a vehicle gets better mileage on the freeway than in the city. An EGR valve that is stuck open, a leaking Intake Manifold Gasket, a defective Mass Air Flow Sensor, a weak or failing fuel pump, or a plugged fuel filter are some of the many causes for a lean misfire.
Mechanical Misfire
Mechanical problems can also cause an engine to misfire. Common causes of a mechanical misfire are worn piston rings, valves, cylinder walls, or lobes on a camshaft; a leaking head gasket or intake manifold gasket; damaged or broken rocker arms; defective fuel injectors (and/or the electronics that control them); and a slipped or incorrectly-installed timing belt or timing chain. Generally, this type of misfire has more of a "thumping" feel to it. It is usually noticeable regardless of engine speed; in fact, it may even intensify as the engine speed increases.
Powertrain Misfire
Sometimes, the engine has nothing to do with a misfire. One common cause for "jerky" performance that feels like a misfire is a problem in the transmission and its ability to properly up- or down-shift. If the misfire occurs during higher speeds, it could be a problem with the operation of the overdrive gear or a chattering clutch in the Lockup Torque Converter. If the vehicle jerks or feels like it is "missing" during deceleration, it could be due to harsh transmission downshifts, badly warped rotors, out of round brake drums, and/or sticking brake pads or brake shoes.
Make sure that you have the vehicle properly inspected in order to determine the root cause of the misfire. Entire engines have been replaced to solve a wrongly perceived mechanical misfire problem that was actually rooted in the transfer case, transmission, driveshaft, or front/rear differential.

Daniel Dillon has twenty-two years of experience as a licensed Smog Technician in California. He helped write test questions for the California Smog Technician Exam and has performed Consumer Assistance Program and gold shield diagnostic work for the state. He was also an instructor for SnapOn Tool Corporation.

you could also try this link...

https://www.google.co.uk/webhp?sourceid=chrome-instant&rlz=1C1CHBD_en-GBGB719GB719&ion=1&espv=2&ie=UTF-8#q=VAN+still+miss+fire

hi Jhlightcap.

The Common Problem: Rough Running Engine

A properly-operating engine should run smoothly and without excess noise. If your engine starts operating in a manner that gives you the perception of "running rough", it is likely due to a handful of common causes. A mechanic would investigate these common causes first in order to rule out a simple explanation for the engine's unsatisfactory operation.
The common causes for rough running in an engine are:

• Engine miss
• Vacuum leak
• Dirty fuel injectors
• Carburetor problems
• EGR valve
• Ignition coil
• Spark plug wires
• have a look at this link.

Rough Running Engine James on Engines 2

This could be caused by a few things, most commonly the engine may develop a misfire due to worn valve seats. This fault will cause the Check Engine Light to illuminate. Replacement of the cylinder head may be required to correct this.

Well this could be caused by a number of things. But the most common cause is an "engine miss." You could have 1 cylinder that has stopped firing. This will cause a very rough idle and very possibly shake or shudder whenever you accelerate. Another cause may be a main "vacuum hose could be disconnected" from it's port. Vacuum leaks cause engine shake at idle. Check for loose, cracked, or disconnected vacuum hoses under the hood. The third and least likely cause is a "broken or worn motor mount". If the engine is not securely held down in place by all the motor mounts, it will vibrate excessively and cause a shake at idle. The engine miss and motor mount problems are 2 issues best left to a professional to tackle. But as I said, you could tackle the vacuum leak issue yourself by checking under the hood. Hope this helps, good luck!

please read about causes of this misfire in the engine.
The most common misfire causes on the cars I've worked on have been:

1. Spark plugs
2. Spark plug wires (most common)
3. Ignition coil
4. Fuel injector
5. Wiring to fuel injector
6. Timing Belt
7. Vacuum leak or stuck open EGR
8. Contaminated fuel or bad fuel pump
9. Weak compression
10. Blown head gasket

this indiacates a serious engine problem that is causing possible damamge, check codes immediately, common problem with that year blazer is bad injector and sometime fuel spider. causes fuel not to work properly in some cylinders and causes lean conditions over compensation by computer and some run rich and cat gets runned, also over drive lockup will not work

My first thought for a solution of your problem is plug wires. You have replaced some common problem areas for this situation but the plug wires are the most susceptible for causing a miss after engine is warmed up. Try replacing the spark plug wires and let me know what happens.

Lefty64

I would check for a broken springs, very common. As for the missing, is there a check engine light on?

it sounds right, it is called a light load miss. it occurs mostly at 45-50 mph on slight incline and it feels like a bucking or hesitation. It commonly ocurs when there is carbon tracking on a spark plug porcelin (sp) . note . if the porcelin has carbon tracking so does the plug wire boot. the spark will travel through the carbon track in teh boot after plug replacement causing premature failure of the plug. it is a good idea to replace plugs and wires if this is the cause of your miss.