back fire threw intake tube
 

ok here is what I did so far I did yet another tune up with wires and yet another coil pack. still getting a miss fire in cylinder 1 once in a blue moon and also it goes threw the intake as well. I cleaned out the maf replased the map and iac as well as the fuel pressure sensor. it still does it every other week. I am stumped. the plug I pulled out of number 1 looks the same as the rest. no corrosion on it to cause a back fire on it. would it be the pcm going bad or is it some thing else like the fuel pump. I had it replaced a month ago the dealer was thinking it was it and it is not. so that bill just got flushed down the drain I don't have the money to keep throwing at it because where I work just keeps us just shy of getting help. so I cant afford the car to be down and throw nonneeded money at it. any help would be welcomed.

things that are new

plugs wires coil pack

fuel pump and reg

new map sensor and cleaned out maf.

oil in trans and engine just changed. yester day

so all maintenance is up to date other than a new engine and power management system.

more info on the vehicle. year make model engine?

e3 spark plugs are a gimmick and could be causing issues for you as well. our system already uses a pretty hot spark and IIRC the e3 are capacitor plugs and this would interfere with the why gm plugs fire. GM v6 engines use a waist spark system where it loops the spark thru two cylinders at a time say into #3 and out thru #6. so when #3 is sparking just after compression, #6 is also seeing a spark just after exhaust. if the e3 capacitors interfere with the flow of spark energy in the opposite direction you could deff see misfires