I know that black is too rich and white is too lean or vice verse, but most of the plugs have black and white on them. I thought the best mixture yields lightish brown results?

if the pics dont show, its probably imagestation, they're always on and off when i host pics from them.

cylinder 1:

cylinder 2:

cylinder 3:

cylinder 4:

I just need help because im wondering why im throwing codes 71-74(cylinder 1-4 misfires). I have NGK wires also and they seem to work fine because when the car is idling, i pulled each wire out 1 at a time and the car bogged on all four wires.

the car is a 99 si with bolt ons and fpr set at 40psi

 

how many miles on plugs? cyl 1 and 3 look bad, try a new set of plugs. go about 2 hwat ranges colder than stock, ex:stock ngk # ****-11 go to ****-9 let me know how it works.

 

How many miles on the engine? What kind of fuel injectors are you using, and how long has it been since they were properly cleaned?

 

98,xxx miles

stock injectors

never cleaned

 

Those plugs all look great from here. I would check the resistance of the plug wires, and maybe the coil. Hows the gap on the plugs, if its excessive it may be too much resistance under load. There isnt much of an engine load at idle, so it might be difficult to tell just by pulling plugs wire with it running. Unless you could pull one while your doing 80 up a hill.

Dont worry about cleaning your injectors, there's additives in the fuel for that.

 

Just by looking at the pictures there is a lean condition on #3.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostn420 &raquo;</TD></TR><TR><TD CLASS="quote">Dont worry about cleaning your injectors, there's additives in the fuel for that. </TD></TR></TABLE>

Whether there are additives in the fuel or not, injectors still get clogged or develop flow problems. Educate yourself: http://www.rceng.com/service.htm#INJECTOR