8
questions

Hi everyone. I replaced my battery tonight because my car would not start and left me stranded three times in the past few days. After replacing the battery, the car started fine. I left for work tonight and as I was driving, I noticed that the RPM needle was wavering every so slightly the entire time I drove. The check engine light is on. The car is normally very smooth and you don't even hear the engine when it's on, so I immediately noticed that the car was shaking/shuddering the entire time I drove and I could hear that the engine was running louder than normal. I have never had problems with this car and this literally all happened immediately after the battery was replaced. Please help!

All but the driver's side door lock quit working either by pushing the button or using the remote. I was told it was the ECU and needed to be replaced. How difficult is it to do it yourself? It looks pretty easy in how to manuals. Also how much should it cost to have someone else do it? Or is this not likely the cause of this problem?

All happened at once when I went to honk the horn I have a code tester no codes errors

my car is in good condition and i dont rag it out i only drive from point a to point b.....why do you think the check engine light is coming on?....im getting your oppinion so i dont get ran over.....thanks

Will the OBD system alert when the PCV Valve needs replacement? THANKS!

need to be loosened or removed?