P0303 Jeep - 99 grand cherokee

Question

i did a complete tune up to my grand cherokee @ 2 weeks later the check engine light came out with the p0303 code i took it to a mecanic and he change the spark plug again it run good for like a week and then it died on me on a red light twice i had to put it on neutral to start it so i took it to the mecanic again so he switch the cylinders from 1 to 3 and a new spark plug and now the same thing happen code p0303 so i ask him what was it and he said is the head and its going to cost me @ 600dollars could it be something else? i else heard abouit putting a spark plug adapter? what is that for?

Answer 1

P0303 Misfire cylinder 3

This is mechanical, when you have a misfire there is no cylinder contribution from that cylinder, , to verify the cylinder head , a compression test or a leak down will expose the problem ,as for the sparkplug adapter these where used for vehicle that had oil leaking into the combustion chamber