Any experience out there with receiving NIB "bad" plug? I just changed plugs on my 914-4 2.0 and its running rough. Pulled the plug wire on #2 and no change - pulled the plug and it is fouled - after maybe 5 miles and apparently has no spark. Regrettably, not anticipating this, I tossed the old ones. Guess I'll be at the parts shop on the morning. Anyone run into this lately?

Nope. I Use NGK.

I run NGK in EVERYTHING if I can.

In 40 years I've had 1 NGK plug that was bad from the git go...

It's uncommon even for Bosch but possible on eveything.

It's also extremely easy to buy counterfeit plugs and not realize it.

Especially the expensive Iridium type...

Now, if two plugs foul out in the same cylinder, I would look at other things.
First thing I'd do is to use a stethoscope on the injector. Make sure it's "clicking".
If it's stuck open (and quiet) it could cause what you are experiencing.

Bad plug wire might do it too.

Never had a spark plug fail right out of the box. Never.

But, it could be a fake part. Stories about fake parts seem to be a thing now.

Did you check to see if it's getting a spark at that plug? Swap that one with one from a cylinder that is firing and see if you're getting a spark.

"apparently has no spark " Yeah, it's either getting a spark in that cylinder or it isn't. We just have to know

NGK also!

What type of plugs did you put in? You want to be sure you run just the basic copper plugs. All the fancy exotic metal plated electrode plugs tend to foul out very easy due to the tiny electrodes.

Yup NGKs, I run a little hotter #6. PMO a little ruch. Mark

These days anything could be poor quality or counterfeit. Any car parts I care about, I make sure to buy from a reputable supplier (I.e. not Amazon). If you trust supplier, buy another plug and see how it goes. If you have any question, but another set from a good supplier. I’m a recent convert to NGK after many years of using Bosch.

Counterfit is a HUGE problem with NGK.
Saw a set next to real. What was most interesting was the on the fakes the printing on the box looked better than the real ones.

Thought this was interesting - my latest box of NGK's.
According to that site, they check out.
Click to view attachment

Thanks to all for responses - especially about fake parts - never thought about that. Turns out it wasn't the plug, it was a fouled injector. I just needed a second set of eyes to watch the ignition sequence. Pretty sure I got the plugs from Rockauto - and I've never had bad parts from them. My bad.

Bought a set from advance.NGK. One was bad. You can check them easily with a timing light.

Kevin