Rep Power: 265

I just bought some new non-oem bosch plug wires for my 97 civic, and I feel like the performance has gone down, considerably, but it could be my imagination (I doubt it). I also replaced plugs with stock non-platinum Denso's, but I doubt the plugs are the issue.

Other than that, platinum spark plugs are NOT good in honda civics. I remember about a year ago I posted on this forum that I couldn't start my car. Fuel was leaking into the spark plugs and I was getting missfires. I troubleshooted until I gave up, and I eventually took it to Honda. Honda didn't know what was wrong either, then they called me the next day and told me it was my bosch platinum plugs! They had to replace the plugs with NGK's and I had to get a new starter coil because I wore it out trying to start it over and over. The issue was NOT the starter, because the plugs were getting missfires and fuel inside of them.

All of this costed about 350 dollars.

The mechanic specifically told me NOT to use platinum plugs in my Honda civic! He told me to use ONLY what was recommended in the book, which are standard NGK's and DENSO's. After he replaced the parts, my car felt different in a good way, and it worked perfect. You're probably thinking, 'well I have no problem with my platinum/iridium NGK's,' and you're probably right, for now. I will tell you that the problems with my car didn't occur over night. The platinum bosch plugs were in there for YEARS, and only after a long period of time did my car start behaving improperly. Eventually it wouldn't start.

Any way, that's why I bring up the plug wire question. Maybe these are problematic as well, even though they are bosch's.

 
Rep Power: 0

Don't listen to your mechanic, platinum plugs are OK. The important thing about a spark plug is it needs to be conductive. Also important is the behavior of that metal at high temperatures. Copper is your standard style spark plug, to be clear, and this works fine. Also platinum works fine, and so does platinum/iridium. One part of that plug is grounded, the other part conducts a current... static charge... spark! And that's it, you have your energy of activation to begin combustion.

Now the problem you might have had... incorrectly gapped spark plugs, corrosion on the contact points, loose connections? I don't know for sure but some of my suggestions nonetheless.

I can tell you this though, if you use any type of forced induction, then stick with the copper, it makes a difference for those applications. I don't understand why myself, but I believe It has more to do with the size and other properties. I think you get detonation with thin platinum/iridium plugs while boosting or spraying.

 
Rep Power: 811

i always use ngk copper plugs in my 02 and always have good performance better than stock double plats. all those new fancy plugs are good for is lasting a bit longer at the expense of performance. and bosch parts never touch my car. ngk=honda

 
Rep Power: 265

Update: Finally had time to replace Bosch spark plug wires. I'm posting this a week after I changed to NGK wires. The car runs AWESOME on the new wires (the Bosch's were brand new too). I have gained, no exageration, about 20% more power on the stock NGK plugs. I will update this when I test my gas mileage, which I believe was suffering with the bosch wires. We will see...

Conclusion: Don't put bosch in your Honda.

To second poster: I disagree. I believe that the only plugs that should be in our civics are those that are listed in the stock manual. (Denso and NGK) I have Denso in mine and the car feels great.

 
Rep Power: 301

My $.02.... NGK all the way for honda. Have tried different things in different year hondas. It always comes back to NGK. Honda motors run best with NGK wires, plugs, etc. NO Bosch, ever. My Nissan too, btw.