Have 2000 hyundai, it starts rough and spits and sputters first 30 sec Obd code reader pulls up codes ideas fi

Question

i have generic obd code reader it pulls up 3 codes 2 are o2 sensor heater circuit malfunction (bank 1,sensor2) and bank1 sensor 3 any ideas on how to fix? i replaced o2 sensor by manifold 6 mos ago and it never got better-maybe a little (i had replaced it cuz it pulled up o2 sensor faulty code) this problem seems more like sluggish to start and takes 1 min or 2 to warm up...the throttle will do nothing the first min or two till it warms up really good then it seems ok tuned it up last year...plugs and wires...what else can i do...motor seems healthy otherwise..uses no oil...acts fine other than this when you first start it and run it..idles fine...somebody please help!

Answer 1

O2 Sensor? Probably NOT the problem.
People like to blame the O2 sensor for the problem because that's where the computer fault appears.
However, nine times out of ten, it's not faulty. It is simply reading a condition in the engine that is causing it to send a signal to the computer that there is a fault in the exhaust emissions mixture.
A fouled spark plug, loose spark plug wire, a vacuum leak, dirty injectors, EGR valve, weak fuel pump, dirty fuel filter, weak ignition coil, plugged air filter, on and on, can all cause the O2 sensor to register a fault code.
Before you yank the O2 sensor and replace it, check all the basics first.

Answer 2

The reader gained't come across something linked with the complicated starting up. The OBDII device would not even care about a lot till the engine is operating, a minimum of no longer issues which will prevent the engine from starting up. the astounding clue is that fooling with the accelerator pedal makes a distinction. maximum ECUs, even in the present day, keep 2 of the former carburetor features as long as there's a Throttle position Sensor to document to the ecu. All will produce a lean blend (for clearing flooded intakes) if the throttle is held down via the undeniable fact that shall we optimal air by and the ecu would not attempt to strive against that. those automobiles with TPSs in many cases richen the starting up blend in case you depress the throttle each and every of how (each and every now and then provided that you do it 2 or 3 cases) with the ignition on. It sounds like it truly is what receives your engine all started - richer blend. you may be sure that by utilising attempting a burst of starting up fluid contained in the intake earlier starting up the engine. If the engine fires with out delay all it needs is more beneficial ideal gasoline delivery. the same old reason behind complicated starting up concerning gasoline delivery is that the gasoline rigidity bleeds off the gasoline rail at the same time as the vehicle sits. once you're trying to commence it the gasoline pump tries to seize up, causing lean blend and sending the ecu off in a hunt for the mystical injection time which will make it artwork, even at the same time as the rigidity is coming back to regularly occurring. if so, the engine ought to commence frequently in case you go away the foremost contained in the "on" position some seconds (like 3-5 seconds) earlier starting up the engine. If that produces solid starting up you may wager the rigidity is bleeding off. the most elementary reason is a leaky verify valve contained in the gasoline pump, and that is an intense priced restore. Many drivers - like me - regulate by utilising leaving the ignition on for a second earlier starting up.

Answer 3

O2 sensor was a good first choice, but you might want to check the thermostat. If the ignition computer is getting invalid information about the temperature of the airflow you can get the symptoms you describe.