I have a 1990 Acoord EX, and It wont pass the emissions test. This is my third time. I did a tune-up, oil change, cleaned out the egr valve and replaced the o2 sensor. Since I replaced the o2 sensor, the check engine light comes on and it gives me a code 41, which i think is the oxygen sensor heater?. I dont know what do do next. It failed on the nox and hc. I tried a few tricks like, higher octane fuel, and adding some heet into the gas tank before the test. If anyone has any input please let me know. Thanks.

 

reset the ecu....if it is still throwing code 41 you o2 sensor is bad. doesnt matter if you changed it or not, you gotta get another one. and i dont know if you have read it here or not but you gotta pony up the dough for the honda one. if you o2 isnt reading right...you will never pass emissions without paying someone off at the testing center. you may have a wiring problem though too. sometimes that o2 wire will rub on a halfshaft and mess up.