Well,I think you hit the nail right on the head.Threw a CEL and took it to the shop that did the engine. They said it was a misfire in cylinder #1. Wanted to charge me 150.00 for plugs and wires. Told him I would do it myself. 60.00 later, car runs like a dream. now I am getting decent gas milage.

BTW - it did have Bosch plugs in it, all of them were gapped at .050 not the reccomended .040.

 

If they were plat's you aren't supposed to gap them. I think that is probably one of the problems with them...

 

Just to stoke the fire of debate a little here on platinum plugs.... Platinum plugs are supposed to be gapped or at least checked for proper gap, if they are the single electrode type. The multi electrode types are set from the factory, Unless you notice that one is way noticeably out of wack out of the package, or you dropped one while fumbling with them, they are fine. And as far as the Bosche platinums go, I have been running the Bosche platinum +4's for about a year now with no problems.... I repeat no problems.... The truck runs beautifully on them....so If anyone is getting some kind of skip or anything, I would think to also check your fuel injectors.....or for a bad coil... I have 4.7L no cap, rotor, or wires... just coils and plugs. Good luck, Happy tinkering.... Jay

 

I still say they're crap. My D ran fine before them. After install it was ok but one night after work I had to keep my foot in the gas to keep it going till it warmed up. I picked up Champions the next day and it ran better than ever (the previous owner put some different brand plug in even though it only had 30k miles on it when I bought it). I tried the bosch +3's or w/e they are. They are garbage in the D I guess you got lucky.

 

I went from stock champions to the truck champions and now to the iridium champion plugs. So far the iridium championplugs runs best. These iridium plugs are very hard to fowl. My wife's 92 maxima was burning way too rich from a stuck open injector and the iridium plugs still fired without problems. Before those iridium plugs were installed on the nissan, I had to change out that plug where it had the bad injector every 10k or so because the plug eventually got fowled up from the very rich mixture.

My D starts super easy and idles very smoothly with the iridium plugs.