The fact that your car was running fine after the plugs & wires were replaced, but then suddenly started to misfire 2 weeks later is a big clue. It is unlikely something that has been building up for a long time. Here’s what I’d do if it were my car, in order:
- This is most likely an electrical firing problem. First thing to do is check all the high voltage electrical connections (the spark plug wires and the common wire going to the distributor cap), and if nothing noted, then replace the the distributor cap. Inexpensive.
- To rule out injector problems, test the fuel injectors for equal fuel output. Don’t do this yourself unless you have expertise on fuel injection systems and their maintenance. Good mechanics know how to do this; they just pop the injectors, insert them in separate test tubes, and run them all for 5-10 seconds simultaneously, then they measure to see that all test tubes contain an equal volume of gasoline. It doesn’t take much time to do the test, so it shouldn’t cost more than $200 or so for that.
- To rule out compression problems, test each cylinder. They should all have more or less the same compression. “OK” says 125 is a low compression, I don’t know whether it is or not, but it is unlikely all the cylinders would go from good to bad compression at once. If they all measure more or less the same, compression isn’t the problem. A compression test takes less time than the fuel injector test.
- If you still haven’t figured it out at this point, your problem is probably some problem in the electronic ignition system. You could try simply replacing the coil if you wanted to take a gamble. You’ll probably need to find a mechanic who has specific expertise on your car to fix it at this point.