97 Tacoma with codes P0300 and P0301

I've got a 97 Tacoma with a 2.7 ltr engine. After getting those codes(P0300 & P0301) I checked plug gap and cleaned plug wire. I cleared the code and after about 75 miles it has come back. Any advice will be appreciated. Thanks
The 300 is a random misfire & 301 is cyl #1. A quick check on the ign you could do would be switch the #1 plug & wire to 2 different cylinders if the misfire moves to that cylinder then it would be a bad plug or wire depending on which cyl came up....
The problem with switching spark plug wires is the #1 wire is too short to reach other cylinders. Figures! I did check the injector and it seems to be fine. Any other suggestions?
My question is when was the last tune-up? Are the plug wires original equipment? If you wet the plug wires with a spray bottle of water while the vehicle is idling in the driveway does the engine skip? Please remember, we don't have the vehicle here in front of us so we can't physically see what would be obvious if we were under the hood.

Steve
I changed the plug wires about a year ago. I will try spraying them with water and see what happens
As Sidom suggested, don't overlook the spark plugs. You can swap #1 & #2 plugs to see if the misfire transfers to #2. If this has a conventional distributor cap (I'm too lazy to check. LOL), examine the inside for a carbon track.
Loren
SW Washington The plugs are fairly new, but I will try switching them up. Also, no distributer but I happen to have an extra coil pack. I'm going to swap them too and see what happens. I'll let you guys know. Thanks for the advice so far!
I switched spark plugs and put a different(working) coil pack on and got the same reading(p300 & p301) I also sprayed the plug wires with water as someone suggested and didn't notice a change. Does this mean it's the plug wire that's bad?
It's possible, now I'm assuming there is a noticeable miss in the engine to go with the misfire.

At this point this is where a scope would come in handy to check the KVs of the wire. I believe there are resistance reading you use to ohm the wire and check that way but I've never been a big fan of that, a lot of secondary failures I've found happen under load where the failed part actually passed a resistance test and would only break down when hot.

If you have a compression gauge a quick reading might not be a bad idea.
So the codes came up again. I've switched plugs, new coil pack, switched plug wires and sprayed them with water. So I guess perform a compression test? Don't have a guage, are they expensive? Also, should I get a plug wire tester? Thanks.
Well you've already swapped plugs, wires & have a new coil pack so barring anything really weird, the secondary should be ok. Depending on how hard it is to get to, swapping the injectors would help eliminate that as a problem.

As far as compression gauges go, the price varies obviously depending the quality.

One thing you could do before buying any of this would be to get a can of carb clean and spray around the intake manifold any other vacuum source close to the #1 runner while the engine is running to make sure you don't have a vacuum leak. Any rise in the idle while spraying the cleaner on any particular spot would indicate a vacuum leak.
So far I've swapped plugs, plug wires, and coil pack. I also tried latest suggestion by spraying carb cleaner, got no change in idle that I could tell, and I swapped fuel injectors. I am still getting the 300 & 301 codes. Any other suggestions would be appreciated!! Hopefully it's not a new engine.
Well you've pretty much swapped all the easy stuff that you can. I think it's time to get a compression reading to make sure we are working with a good hole. I don't remember if you posted if you had checked injector pulse, but that wouldn't be a bad idea either if you haven't.

So I did a compression test and the #1 cyl is way low(but steady) at about 105. I squirted some oil in and got the same reading. The #2 was about 150 and the #3 and #4 were at 170. Haynes book says the min/max is 127/178. I also tested vacuum and got 15in of vacuum. So what should I do next? Thanks!
Well #1 is pretty low, that sounds like your culprit. Usually if it's the rings, doing a wet test like you did would raise the compression. The next step would be to do a leakdown test to see where you are losing your compression at..........
Sounds like one of the intake valves arent closing completely which explains the backfire.