1998 civic ex engine light came on
 

my engine light just came on ,on my civic i was going to change the o2 sensor but im hearing that there is 2 o2 sensors on this car is that true?also when i opened the hood i saw some white smoke just a little bit comming from the top o2 sensor should i change that one ,im seeing that they are about 80$ to buy.

there is a primary and secondary O2 sensor yes but they should be alot cheaper then 80 dollars maybe for both would cost 80 . only use DENSO or NTK sensors honda uses both yours came stock with DENSO i believe.

so bosh is no good why

You should read the code(s0 to confirm it may be an O2 sensor issue before buying any parts. If you get the heater codes for both sensors, it is likely the fuse 15 problem not a bad sensor.

bosch is good for domestic vehicles not japanese cars these cars come stock with DENSO/NTK sensors you can use bosch but don't say i didn't warn you. also i believe denso is cheaper.