Beware of Fake Spark Plugs

Ok, so here's a question. I recently got a P0308 error code, Cylinder 8 Misfire Detected. I swapped the coil pack with cylinder 2, and the error stayed with #8. The last time this happened, it was cylinder 3 and the solution was replacing the two spark plugs. Not wanting to mix up spark plug types, I bought exact replacements from RockAuto. They are MOPAR SPLZTR5A13, for $11.16 each.

So, since now I have the same error, this time #8, I'm thinking it's time I might as well replace all the plugs and be done with it. But 16 plugs at 11 dollars a pop is $176 bucks. RockAuto has a lot of other choices, like:
Platinum - priced from $2.69 to $10.43
Double Platinum - priced from $2.61 to $9.19 (supposedly better)
Iridium - priced from $3.43 to $8.25 (supposedly best)

That's a big difference in cost. And they're all well-known manufacturers, Autolite, NGK, Champion, ACDelco, Bosch...

Does anyone out there have any real experience with spark plugs and can you recommend a certain one, or definitely rule out a certain one? I don't mean some adage like, "don't buy the cheap ones they're always bad", or "expensive ones are always better". I mean has anybody tried some of these and had some actual results?

TIA,
Rick

 

Ok, so, here's the story. Two years ago I got a misfire code on cylinder 3. Immediately assumed it was a coil pack, ordered a new one, swapped it out, and still got the same P0303 code. So I removed the new coil pack, put the original #3 coil on cylinder #1, and moved the #1 coil to #3, just to get them all back to original, and swap #1 and #3, which is what I shoulda done right from the start. Dummy me. As I figured, the misfire code stayed with cylinder 3. THEN... I swapped the spark plugs from cylinder 3 and cylinder 1 and this time the error code moved to cylinder 1, P0301. That confirmed it was the plugs, so I bought two, replaced the 2 that were now in #1, and life was good. No error. No misfire. Engine running smooth again. At that time, the car probably had about 76,000 miles on the clock.

Now it's today. Misfire cylinder 8. Swapped the coil pack with cylinder 2. Still showing error on 8. Today I swapped the plugs between 8 and 4, just cuz 2 is harder to get to, the fuse box is in the way. Car is still running rough but I took it for a short drive and it hasn't thrown a code yet. I'm expecting the error to move to cylinder 4. We'll see.

Car has just shy of 80,000 on it now. I'm retired so I don't drive as much as when I was working every day.

Tom, you're right about the plugs. Mine has the same NGK PLZTR5A-13. That's probably why I bought the MOPAR ones from RockAuto, the number shown on their site is SPLZTR5A13 so that looked like an exact replacement. If you go on there now, and click on that one, the picture is of the NGK plug! And I verified by pulling one of my #1 plugs that's what they sent me 2 years ago when I ordered the two to replace the failing ones.

So, since it seems like they're all getting ready to go, I figured I should just replace 'em all and be done with it. But I'd rather not buy 16 of the most expensive ones. Have you replaced yours with the iridium ones?

 

Cool.

But, back to my original question, does anyone have actual experience replacing plugs, (on the 6.1) what kind did you get, and how well did they work?

 

Get the stock plugs from a Mopar dealer.

 

So tom when did you get garage?