Well, I'm entering the stumped zone and looking for thoughts on what to check next...
It's a '99 Outback, manual trans, with 188k (motor rebuilt at 150k so the story goes). I've owned it now for 5 months or so. Right off the bat, the CEL was throwing a P304 cylinder 4 misfire; it was very intermittent and would clear itself after the 5 start/run cycles of not repeating. This went on for months where the same p304 would throw every few weeks and then reset itself. Recently it began happening more and more often and the idle began suffering, alternating between low and normal, getting rougher as well. Last week, the CEL got really pissed and started flashing every few minutes while the idle and low speed stumbling grew worse.
I started searching through all the old threads I could find and it seemed the first step was plugs/wires. I replaced all four plugs and wires last night with NGKs and cleared the codes when done. Two miles down the road, the p304 misfire threw again. I picked up a new ignition control module today and popped it on at lunch and cleared the codes again; the idle still seemed rough and within 5-6 miles, back came the light. I haven't been able to read it yet, but I'm betting it's the same p304 cylinder 4 misfire (the only code that keeps tripping).
So, where's my next logical step? Injector? Fuel rail? Some simple test to try first? The idle now spends a lot of time at 500ish and the whole car has a good shake. It seems to stumble below 2000rpm and, for the most part, smooths out completely at 2500 and beyond. I've seen some of the suggestions in other threads, but many of them complain of multiple codes being thrown together, i.e. multiple cylinders misfiring at random; not sure if the fact that it's constantly the same one plays any specific role here.
Thoughts?
I appreciate it!
It's a '99 Outback, manual trans, with 188k (motor rebuilt at 150k so the story goes). I've owned it now for 5 months or so. Right off the bat, the CEL was throwing a P304 cylinder 4 misfire; it was very intermittent and would clear itself after the 5 start/run cycles of not repeating. This went on for months where the same p304 would throw every few weeks and then reset itself. Recently it began happening more and more often and the idle began suffering, alternating between low and normal, getting rougher as well. Last week, the CEL got really pissed and started flashing every few minutes while the idle and low speed stumbling grew worse.
I started searching through all the old threads I could find and it seemed the first step was plugs/wires. I replaced all four plugs and wires last night with NGKs and cleared the codes when done. Two miles down the road, the p304 misfire threw again. I picked up a new ignition control module today and popped it on at lunch and cleared the codes again; the idle still seemed rough and within 5-6 miles, back came the light. I haven't been able to read it yet, but I'm betting it's the same p304 cylinder 4 misfire (the only code that keeps tripping).
So, where's my next logical step? Injector? Fuel rail? Some simple test to try first? The idle now spends a lot of time at 500ish and the whole car has a good shake. It seems to stumble below 2000rpm and, for the most part, smooths out completely at 2500 and beyond. I've seen some of the suggestions in other threads, but many of them complain of multiple codes being thrown together, i.e. multiple cylinders misfiring at random; not sure if the fact that it's constantly the same one plays any specific role here.
Thoughts?
I appreciate it!
