1999 Nissan Maxima GLE starting issues/ EGR valve code

Hi guys,

I have a 1999 Nissan Maxima that died on me last night. It would not start at all. we were able to jump start it once and when I got to autozone to check the battery, they said the battery was fully charged (they measured it with the car on and off). After that we could not even jump start the car anymore. I took it to the local repair shop this morning and they are saying it’s a problem with the starter. They are now replacing the starter, but they also found an EGR valve and knock sensor error codes. The EGR valve was replaced a year ago and they are saying there’s too much carbon built up already which would probably mean that I need new EGR valve. Any ideas if the two issues are related and how I can fix the EGR valve issue once and for all? I don’t believe it’s time to change the valve again. Is there a good fuel cleaning system that I can use to try and get rid of the carbon built up? THANK YOU!