i have a 98 subaru legacy outback i put new plugs and wires on it when it is at a idle it runs rough and then the check engine light comes on code is always cylinder 4 misfire it runs fine other wise any ideas
If it started running rough AFTER you put the new plugs and wires in, I would take a multimeter and check the continuity of the wires, make sure the spark plug in cyl 4 is seated properly, and check the coil. There are threads you can search here for the procedure to check the coil.
If you put the plugs and wires in to try and fix the running rough (seems more likely), than I defer to one of the more experienced gurus here.
i am going to try a nother new plug on that cylinder it was doing it when i got it a few weeks back when driving it it runs fine was wondering if a fuel injector could be clogged and not allowing enough fuel when at a idle
the first thing i did was run seafoam in it the plugs are denso plat and the wires are autolite the problem was there when i got the car it has 160,000 on it i checked the plug before i put it in the electrode was not bent i used a spark tester and coil and wire at plug end are firing a good blue spark
i used a spray bottle at nite there were no arcs on any thing
^^^^^ +1 on compression test. And swapping injectors with another cyl would confirm/negate the injector theory.
recently, a guy on a Forum discovered his dead cyl 4 had only 25 psi compression.
some folks have problems with plug wires other than OEM. I have no idea about success with Autolite. If you still have the old plug wires, you could try substituing one in on cyl 4 as a test I suppose.