caveboy

I have a 1990 civic 1.5l that will not pass emmisions test. high nox
i have put a new cat. new oxygen sensor , new air filter. oil change , coolant change , i have tried retarding the timing , no luck, at my wits' end .
any ideas?
caveboy

C.R.E.A.M.

iTrader: (1)

spark plugs,wires,distributor cap,rotor,coil and pcv valve.Did you change these parts?
lmk I have all of the above parts new and I could install them for you.

caveboy

update:
found timing belt advanced 3 teeth on cam, also found out that "bosch" o2 sensors do not play well with hondas, changed o2 sensor to a "denso" now my car makes cleaner air than it takes in!!! passed emissions !!! BTW the car has 300k miles on it, still gets 38 mpg!!!!!
WAHOO!!! life is good once again!!!
caveboy

LukeJone

Change the oil, immediately go for emission insp. You'd be surprised at the impurities / gasoline in old motor oil.