Car Issue after replacing O2 sensors and oil change.

[bschunck]

I just recently replaced my bank 1 and 2 O2 sensors in my car. Right after that I did my routine oil change. Since then, my car has been running very rough. Prior to replacing the sensors, everything ran fine with the exception that I was getting an error code stating my O2 in bank 1 and 2 were running lean. On a recommendation, I replaced them. Now I am getting a Cylinder 4 miss-fire and I'm getting a O2 in bank 2 running lean. My car idles very rough now and I feel a loss of power as I accelerate. I have no idea what could be happening as I haven't done anything drastic other than the oil change and sensor replacement. It's very frustrating and I can't really afford to take it into a shop. Hoping it is something I can do on my own.

I have an 05 Taurus with the regular 3.0L V6 engine.

[sheila]

May check the plug and wire for #4 cylinder (front pass.). Then check the coil pack.

[behlinla]

Read the misfire sticky first: How to Understand and Diagnose Misfires

[WJC]

If you had a p0171 and p0174, you still have an issue you need to address. The oxygen sensors may never have been the problem. Borrow a scan tool that reads live data and get back to us.

[downhill]

Vacuum leaks???? Plenum gasket good???? Check coil and the wires for hot spark of at least an inch???? You might have bumped something loose when doing the work.
Make a very thorough check of hoses and wire connections. Good luck~~

[Breeves002]

I just wanted to add, read what behlinla linked, and also it probably has nothing to do with the O2 sensor or oil change.

[sheila]

^+1 with downhill.

[Bullhorn]

+1^ because your O2 sensors were reading lean that means something upstream is causing a lean mixture, possibly a vacuum leak or your MAF is dirty and reading wrong causing a wrong mixture. but its a problem upstream of the sensors, since your sensors are letiing you know hey check this out!

[bschunck]

Thanks everyone for the feedback. This gives me something to go on and check out what the issue could be. There is a possibility that I may have bumped something when I was removing the bank 1 sensor as it was a bit of a pain to get to. Will post my results once I find out some answers.

[bschunck]

I tried the spark test and I was getting a spark from all of the coils except for #4. Since I need to get new cables anyways to do a tune up, I'm getting a set of cables on order and I will start be replacing the cable on #4 before I go to the next step. I checked all of my Vac hoses and lines and those appear to be ok. I don't have the hissing sound as the one guy in the video noted about being a good sign of a Vac leak.