chevyman1981

hey i need a little help here i have a 96 jmc jimmy with a 4.3 i have the code p0303 and need a place to start to figure it out it is do 4 inspection this month thx 4 your help ever one

maxxman04

p0303 is misfire code fir cylinder 3. i would start with a full tune up with cap/rotor/plugs/wires/air and fuel filter.

chevyman1981

hey thx i will do what do u thnk if i get the code back again wher do i go then ?

maxxman04

compression test for all 6 cyl. the difference between the highest reading and lowest reading should not be more than 10-13psi. also, when you pull the spark plugs, keep track of which cylinder they came out of and condition. post pics of plugs if they look messed up and which cylinder. that'll help us help you too.