So I've been on here trying to solve this problem for a while...new events happened when I was driving to the beach the other day:

For a while now I'll get a misfire, it'll throw a code and set the CEL. I'll erase the code and the car will drive perfectly for a few days before setting the code again (usually after I've been at highway speeds for a while, or after I've been at highway speeds, have slowed down and have sped back up to highway speeds again).

When I was driving to the beach the other day, though, the CEL started blinking. It would blink maybe 10 or 15 times, stop for a little bit, then start again. Anyway after about 4 or 5 miles it stopped completely and after a while it just came on and stayed on like it always does. This happened on the way home from the beach as well.

I've done some reading around and the general consensus seems to be that if your CEL is blinking then you're damaging your cat pretty seriously. If you read my other posts you'll note I drove the car for a while with a leak in the EGR system...any chance that leak fouled my cat and it's just been getting worse since?

 

Have you ck the codes yet?

 

Ck the codes? Maybe I'm bring amateur but what does that mean?

 

No problem, When the check engine light comes on the dash. The PCM will store or have an active code for what circuit that cause the light to go on. When you have codes it helps to find the problem.

 

I didn't know you could do that. Howe could I do it myself? Or do I need more advanced equipment?

 

All I've got is a basic code reader...

 

You can try to use the code reader. But you may need to have someone with a scanner to ck for codes.

 

Your local autozone can usually read the codes too. Post what your "basic" code reader puts out. the '95 model year is the only one that used odbI, which needs special equipment, the odbII is pretty much standard, so you should be OK there.

A pretty common cause of misfire in the v6 engine is either bad spark plugs, spark plug wires. If those are new, not showing any signs of wear, another rather common thing is for oil to be seeping in around the spark plug wells, fowling up the cylinders. The front valve cover gaskets are pretty easy to get to and replace, the rear ones require the removal of the upper intake manifold, which you'll need to take off to replace the spark plugs and wires anyways.

 

That's not a bad idea...I took all the plugs out the other day and there was a little bit of oil in the threads of the plugs, but none seemed to be getting down to the plugs themselves. Nevertheless that's probably the culprit as I know the front valve cover gasket is shot anyway. The plugs and plug wires only have about 15k on them...not that this means they're brand new but they still look alright.

Codes I'm getting:
p0300--100% of the time
p0301, p0303, p0305, p0300--these usually show up 90% of the time
p0302, p0304, p0306--those are about 75% of the time

All these codes are consistent but it doesn't feel like the engine is missing very much. I don't really think it happens all that frequently, it just trips the code when it does happen. If it wasn't obdII I probably wouldn't even notice.

Basically it'll move around to all the cylinders but 1, 3 and 5 seem to show up more often. My uncle is a mechanic and I'm going to take it in to have him help me diagnose the problem for sure before I throw any more money at it. I've been running the car like this for months, though, so I'm pretty sure no matter what I'm going to have to replace the cat.

 

Change the spark plug wires and let us know how it goes. That was the culprit on my V6 Taurus and it had the very same symptoms.