Autolite XP5683-4PK Iridium XP Spark Plug Review: Pack of 4, White Review

Caused a misfire in my 2009 Toyota 1.8 liter engine. Trying to find the error for a month. I've spent hours and hundreds of dollars trying everything else, thinking new spark plugs couldn't be the culprit.

So I decided to put them in but there was no suitable socket. There are 2 standard size spark plug cartridges. I took the piece of rubber out of the small socket and stuck it into a 14mm deep wall and it worked. A spare vacuum hose should also fit.

I bought this and must have bought a return. 3 of these were new and the fourth looked like it had been used and burned. I can't return it because I already have it installed. and my mechanic got rid of the bad one and bought another one from Auto Zone.

Spark plugs must be supplied with factory gaps as they have a very fragile iridium tip. You must not tear them apart yourself, otherwise you may damage them. Added to this were mine, broken as if they had fallen on part of the electrode. 2 out of 4 came like this.

Don't put them on imported cars from Asia. If possible, replace with the same brand that was factory fitted to your vehicle. If not, Denso or NGK are your best choices. I bought them because I thought all candles are the same. After a few headaches, research, and wasted money, I discovered that imported cars, like my Corolla, are designed around Japanese ignition systems.

I installed these goodies myself on my 2015 Subaru XV Crosstrek. they fit really well as described. However, during a test drive, after about 12 miles, the engine began to stutter and shake violently. Had to drive on a local road 30 minutes ago. After further research, people only recommend NGK spark plugs, which are OEMs. I then ordered NGK pkus from Rockauto, installed them, and the engine runs like clockwork. I'm sure the Autolites are good too but they just don't fit my car as advertised or