I have an 08 Maxima at first the alternator went bad and the guy that was fixing it had two projects ahead of me and the last one a truck fell on his arm that being said the car may have sat for a month and a few weeks. Had the alternator replaced now the car jerks not off take off but it’ll catch on. Had the codes read and an engine misfire and two emission leaks were detected. I’ve had all 6 spark plugs and bumpers replaced also the valve cover. Now the car is losing power. Any Suggestions???

 

Try replacing the camshaft and crankshaft sensors. They always go bad on these cars.

 

+10

 

So true..
you said you changed 6 plugs did you reuse the old coil packs?
I hope you didn't use a shop and that your a diyer

 

Seems like the car should throw the specific code for the camshaft position sensor. When mine went bad, it did. But it also had different symptoms, like stalling when coming to a stop.

before you replace them both, you can remove the sensor and see if it just needs to cleaned. Mine had a layer of grime on it and dirt or burnt oil in the holes on the sensor. I probably could have cleaned it so it could get a better reading. If you do happen to have this replaced make sure you buy the exact OEM part that the car came with and not another brand.

What are the exact codes it's throwing?

If the misfires are coming from the two cylinders controlled by the same coil pack then that one might seem pretty obvious.