How long does it take to fix a misfire on mazda mpv cylinder 3?

[angel]

I have a 2000 mazda mpv. The check engine light started flashing.I took to mechanic shop and was told it had codes P1518, and P0303. One is cylinder shutter valve stuck open and other is cylinder 3 misfire.How long should it take to fix this problem? The mechanic has had the Van for 2 weeks now? He says he replaced EGR valve and put some fuel injector cleaner addative. I need help,does anyone know what else I should do?

 

[Richard R]

run it off a cliff takes about 4 to 5 seconds not including the trip that if it makes it

 

[thebax2006]

Find a real mechanic. The work he did so far should only take an hour.