So ive been getting poor fuel mileage lately, and am also parting together a turbo kit for my 90 crx si (200k, rebuilt 15k ago) and figured this is as good a time as any to do a tune up. I have so far changed my plugs, oil, oil filter, coolant, and thermostat. I plan on changing my o2 sensor and fuel filter, is there anything else that should be checked? ( i also plan on replacing the timing belt)

 

water pump, gasket kit check for old rotting hoses. check ur valves ..lol. you know the usual

 

plug wires
pcv valve
distributor cap and rotor
check ignition timing

 

i was also planning on running a compression test as well