Originally Posted by VanessLenin
I have ran into the same problem Check Engine & Trac Off blinking. I also feel that the car is bugging and like there is not enough power. Also exhaust makes a different noise. Took it to the shop 3rd cylinder not working. It can't be a coil because there would be errors on other cylinders as well. I reset the codes and when I started the car everything was fine nothing came back on and the car was responding perfectly. I also know for the fact it can not be spark plugs because I did a tune up and changed all of them not too long ago.
Last summer i was getting check engine light with O2 sensors. I turned them off and then the engine light would come back on and then few days later it would turn off by itself. Since November I did not had any check engine lights coming back nor did i change my o2 sensors. Now we were getting some heavy rains and this happened. I took the cover checked sparks everything is fine. So do you think the problem is in O2 sensors and the time came to change them? Also my shop told me that O2 sensors go at about 2bills per piece and there is 2 of them that needs to be changed. If anyone changed them are there anybetter prices, if so can you post a link. Thanks in advance!
There is always the possibility of the car throwing one misfire code as i've seen it happen before. It doesn't nessesarily have to be related to the plug or ignition components, it could be a result of a fuel delivery issue such as a bad injector or even a compression problem with that cylinder(ie. bad valve seals, piston rings). Depending on the mileage of the vehicle, a fuel system cleaner or injector service can be helpful. One route i would take is to use an OBDII scanner and find out your fuel trims, that can also help point in which direction the problem lies.
As far as oxygen sensor codes, it sounds like you may have a heater malfunction because usually they start to go bad, code may clear for a few weeks, but it will eventually come back and stay on(that's if the code pertains to that). I don't think the O2 sensor is responsible for one cylinder misfire, but if it's a primary or upstream sensor then it may not help. If it is a post cat sensor then it will not effect performance at all, only give you a CEL. OEM Denso oxygen sensors have come down in price and you can pick up a universal(that requires soldering) for $70 or so. A direct plug and play are around $100 or slightly more, but no where near $200. Your best bet is to get the car scanned and post back all of the exact codes to take out all of the guess work.