on sunday it had a little miss like it had water in the gas so put cod reader on cod read cylinder #3 was mising and 1 and 2 are runing len so put new plug in all 6 did not help! put in oxyen sensor did not help so check for vacuum leck used 3 cans of cob. clener no leaks. so put new wires on it was just as bad so replaced coil pack did not help. so put 3 of old plug back in the new plugs was soote! or black ? it mising #1-2-3 put 3 of the old wires back on same thing mising bad reel bad .unplug the map sensor the truck was runing did not do a thing . did not kill it ? it has 160k on it . it act"s like it is out of time ? I just dont know. i am new hear and need all the help i can get . thank you, `123clark, from alabam .

 

Check fuel pressure at the injecter rail port with a gage.
Then come back with the results.
There was nothing to tell you to replace the OX sensor.
There was nothing to tell you cylinders 1 and 2 was running lean.
Only thing you had to go on was a verifiable cylinder 3 missfire.
There may be other issues as the cause but you need to approch it differently than just guessing. It cost more money to do it that way before you might 'get lucky'..
Good luck.

 

You put in new plugs? What brand? If they are Bosch take them out. 99.99999% of the time the 4.2 will run like crap with Bosch plugs. Use Motorcraft, Autolites or Denso iridiums.

 

Thank you for the help. Bluegrass and 97xl but it was auto zone gave me the wrong fairing order ; now i have to clean the egr and the mass sensor and i think i will have it but thank's for helping 123clark