Car problems - any thoughts?

[pete2002]

2003
Hyundai
Accent
4C 1.6L Automatic
GL - i think
No Modifications
~47000

Hello,

My check engine light has come on several times now. Last time this happened it was engine misfire. Last week I also got P0133 - O2 Seonsor Circuit slow response (Bank 1 Sensor 1) and P0137 - O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2.)

It seems like the misfire occurs when I am idling. Yesterday, I put the car in idle to go through a car wash and the check engine light came on several times.

I will probably take it in tomorrow but I am wondering if anyone can provide me thoughts on the cause/causes? If I can provide any other info/clarification, please let me know.

Thanks,
Pete2002

 

[Eli]

My guess is the O2 Sensors. 😉

 

[bruceb]

First, you said you had misfires. Take care of that first. That would include new spark plugs, check / replace the plug wires and since you had trouble in a moisture condition, I would replace the distributor cap & rotor. It only takes a small crack or carbon track to get a misfire.
After that, if you still have trouble with the O2 sensor code, then replace the sensor.

 

[exdeath]

It's possible they are related if the O2 sensors are failing and the engine is running too rich in closed loop and fouling the plugs.

Front and rear sensors failing at once is odd. Did you run any kind of additive or leaded fuel somehow?

Could be a bad harness connection where the O2 sensor harness connects to the main harness, especially if it's at the bottom of the car where it can get wet or snagged easily, or even burned on the exhaust pipes.