Alright, so I am new to the forum and have been browsing through for a while. Currently I own a mazda CX-7 2008. My wife and I love the car, and being as it is our only car I would like to keep it in a good condition. So I bought this vehicle used, as is, from a deal here. After about a month of smooth sailing I had gotten P0302, cylinder 2 misfire. I have spent close to a couple month attempting to fix it.
So far I have replaced spark plugs, swapped coil heads. I had done this early one to prevent any other problems. Now this did not clear the error. We kept driving and hoping I could find time to work on it or find some information leading us to a solution. In that time, eventually I had gotten another code, indicating that the fuel mixture was to lean. This was the point where I went to the mazda service center.
They ran their diagnosis on the car and uncovered that the O2 sensor was not responding. They offered to either swap my coils around for $300 or replace the O2 for $400. Seeing as I have done the coils my self that was not a $300 job. So I had them replace the O2. Once this was done, both errors cleared. We drove for a good week before any misfire came back on. Now knowing what this meant, I was not quite happy. As per suggest of a mechanic friend of mine, we ran some fuel injector cleaner a couple times to eliminate dirty injectors. Another week went by with no error. The lamp came back on and here we are now.
The cylinder misfire, when cleared after cold start does not come back during normal drive time. The engine feels no decrease in power, or hesitation when driving. When idling the engine is a little rough. Rough in that it reminds me of a truck or my fathers old chevy suburban.
Being a college student, I don't have much time or money to put into a car. Sometimes I can find the time to pull it apart and swap parts or inspect things. I have checked to see if I am missing any coolant, or if there is a good bit of white smoke out the tailpipe. I haven't seen any missing coolant or very much white smoke out the tail end.
I also have the shop manual for the car and have been browsing through it to see what kind of tests or inspections I can do on my own.
I come to you on this forum asking for a bit of help or advice if you have any or have any similar experiences.
Thanks in advance,
Aj
So far I have replaced spark plugs, swapped coil heads. I had done this early one to prevent any other problems. Now this did not clear the error. We kept driving and hoping I could find time to work on it or find some information leading us to a solution. In that time, eventually I had gotten another code, indicating that the fuel mixture was to lean. This was the point where I went to the mazda service center.
They ran their diagnosis on the car and uncovered that the O2 sensor was not responding. They offered to either swap my coils around for $300 or replace the O2 for $400. Seeing as I have done the coils my self that was not a $300 job. So I had them replace the O2. Once this was done, both errors cleared. We drove for a good week before any misfire came back on. Now knowing what this meant, I was not quite happy. As per suggest of a mechanic friend of mine, we ran some fuel injector cleaner a couple times to eliminate dirty injectors. Another week went by with no error. The lamp came back on and here we are now.
The cylinder misfire, when cleared after cold start does not come back during normal drive time. The engine feels no decrease in power, or hesitation when driving. When idling the engine is a little rough. Rough in that it reminds me of a truck or my fathers old chevy suburban.
Being a college student, I don't have much time or money to put into a car. Sometimes I can find the time to pull it apart and swap parts or inspect things. I have checked to see if I am missing any coolant, or if there is a good bit of white smoke out the tailpipe. I haven't seen any missing coolant or very much white smoke out the tail end.
I also have the shop manual for the car and have been browsing through it to see what kind of tests or inspections I can do on my own.
I come to you on this forum asking for a bit of help or advice if you have any or have any similar experiences.
Thanks in advance,
Aj
