New Spark Plugs, Engine Light Appear

[WeeYari]

Originally Posted by grvdggr

I can't check codes, I don't have a OBDII reader, can you recommend one?

I'm using one of the cheapest I could find. Nothing fancy, simply reads stored codes and allows you to reset. Since codes are easy enough to look up online, you don't need one of the fancy ones that will read codes, plus provide textual descriptions of the codes. At $50 Canadian for the one I have, it has paid for itself many times over performing diagnostics on my, friends, relatives, and neighbours vehicles. In fact, since unlike my American neighbours, we do not have establishments that read codes for free, at one use, the reader more than paid for itself.

I'm willing to bet that you are throwing a misfire code which usually points to plugs or coils. If this is the case, once you read codes you will know which cylinder is misfiring. At that point, you can swap that cylinders plug for a neighbouring one and see if the code follows the plug to its relocated cylinder. If it does, bad plug. If code appears, but for original cylinder, perform the same exercise with the coil.