Trying to gather information when its recomended to change the plugs. I currently only have a Halltech MF103 untuned..

Questions:
Should I keep the stock plugs at my current mod status?

If recomended to change what should I gap?

If not recomended, what other mods do I need before recomendation?

Thanks everyone!

P.S. I have searched...

 

bump!

 

Here's my standard answer to this:

http://forums.corvetteforum.com/c6-f...ith-boost.html


An engineer supplied this list of problems that could cause this code (points 1-3 are probably less likely, and I feel that Point 4 is the real cause:

1. Electrical System corrosion- primarily noted on the 4 pin connector on the back of the alternator. Which could cause a voltage drop, from the commanded voltage to the alternator from the ECU.( I’ve attached a P0621 diagnostics file from GM.)

2. Possible bad battery (cell) or faulty alternator

3. Aftermarket ignition wires #1 cylinder lead is too close to the alternator causing some sort of interference issue.

4. So the Original spark plugs are Iridium/ Platinum precious metal spark plugs. When switching to the TR5/TR6, which are nickel, the ignition system actually works harder. Traditional Nickel center electrodes require more voltage to fire than a precious metal Iridium/ Platinum, simply because of the center electrode diameter. Next is the coil design: There’s the primary and secondary winding in these coils ( as in most coils)and GM set it up so that between firings of the spark plug there would be a voltage reserve within the coil. Now when you install the Nickel TR5/TR6, that voltage reserve is completely spent on firing the plug every time. This is normal for higher RPMS. At idle the demand voltage is much higher than what the alternator is being commanded to put out. The vehicle is programmed to have the least amount of drag at idle to help keep fuel consumption to a minimum and to not rob the engine of horsepower at idle. So the voltage demand from the coils is more than the output of the alternator and is causes the P0621 code trip at idle. If you want to continue using the TR5/TR6 plugs there are a few ways to fix the problem:
A. Go into the programming and command the alternator to generator more voltage at idle. This can be done with aftermarket laptop tuning software( HP Tuners, EFI Live, etc.

B. Delete the code from the ECU altogether so it is not triggered at idle.

If you want Iridium and want the TRs try the Iridium IX spark plugs. TR5IX/ TR6IX. This may also solve the problem. Not all GM models have a problem with this code after installing Nickel plugs.




That is an accumulation of stuff I've read in here. I've had the TR6 in my car BUT is has FI BUT still I got DIC messages to Service the electrical system. I corrected the DIC messages by installing the LS9 plug in the car. It is Iridium, colder, and smaller gap. I don't think you need to change out your plugs.

Elmer