I have a 97 infiniti i30 with 278k miles on it. it runs good but when the car is cold and first started the engine idles rough and some times cuts off requiring me to give it a little gas to get it going. after the engine is warmed up it idles fine. i checked the codes and i get p0174 (system too lean bank2 and bank1) and p0325 (knock sensor bank 1) could the o2 sensors be dead? seems to me the car wouldn't run at all if that were the case.
could the o2 sensors be dead?
Why not test them?
seems to me the car wouldn't run at all if that were the case.
Incorrect.
You might start with the easy stuff like checking for vacuum leaks, checking filters and spark plugs, and cleaning the throttle body and MAF sensor.
I actually just changed the spark plugs but that didn't help any. im not sure how to test a sensor.
You should be able to see O2 sensor output in your live data.
what should i look for? i don't really know what numbers would be normal lol.
Plenty of information out there on that topic with a quick internet search. Briefly, the upstream sensor should show a continuously varying voltage between about 0.1 and 1.0 volts and the downstream sensor a steady voltage around .5 volts if everything is working OK.