have to replace plugs every month 93 d16

[archuletacr]

hey, i have a 93 civic coupe ex. I have to replace my plugs almost every month cause they get carbon fouled looks like they been in the for years. I also use ngk every time.I also have cracked exhaust manifold it is cracked before the O2 sensor,I was thinking maybe this is throwing off the sensor and screwing up my air fuel mixture, should i also think about wires rotor cap the usual, but that stuff was replaced a year ago. its driving my crazy having to change the plugs so often. I also have problem with my cluth pedal sometimes it make s clunk noise going into 2nd gear and sometimes hard to get in first and reverse. and pedal goes to floor when parked over night i pull it back and its fine but has a lot of play, is my clutch master cylider going out? any help appreciated thanks.

[hany]

i think what damage the plugs
you may have a damage internal parts in the engine which allow the oil to cover the plugs

so check these two factor.

[i_a_n112784]

Fuel additives can also cause fouled plugs, even additives put in by the gas companies. As for the clutch, check for leaks inside the car where the pushrod goes through the firewall, and under the hood as well, that will give you a quick visual inspection of the master cylinder, and look inside/around the slave cylinder boot for fluid.