So one day goin down the interstate, the ranger bogged down, serious power loss, and threw that disgusting blinking check engine light (miss-fire code). So i had the codes checked and it was PO304 and PO305. O yea, and I had just replaced plugs, wires, coilpack, and fuel filter about 4000 miles before the problem. So I checked the plugs (I got the E3's but even replaced them with OEM) and they fire good, checked the wires and they fire good, and checked the coilpack and it fires good. The problem did occur shortly after I had filled up the gas tank, so i thought maybe the injectors were dirty, so i seafoamed the hell out of them...didnt fix it. I had the exhaust pressure tested thinkin maybe the cats were glogged but the pressure was fine. So tonight i did a very simple test...while the truck it running, pull the plug wires for cylinder 4 and see if there is any rpm/power loss...there was not. Did the same for cylinder 5 and no change. I even did that test on cylinder 1 & 2 and i did notice a rpm/power loss (that was supposed to happen, i just wanted a base to know what was supposed to happen). So i switched the fuel injectors from cyl.4&5 to cyl's 1&2...ran that easy test of pulling the plug wires from cyclinder 1 then 2 and there was no loss of power (there should have been) and then pulled the plugs from cylinder 4&5 and there was a power loss (that was supposed to happen), so that tells me that its the injectors.Right? I replaced the injectors and it didnt help one bit. This problem has been goin on for about 3 weeks now. Please help me!!!

 

Well as I can see...No one has a clue about what might be wrong so Im just goin to take it to a dealership and just say...fix it. I know theyre expensive but Ive already spent about $400 going to auto shops and them charging $100 to diagnose it then tell me that its the spark plugs or they just dont know. Its getting really frustrating being able to go only 30mph...o yea, and now cyl. 4,5, & 6 are miss-firing...YYAAYYY FOR ME!!!!!!!

 

Did you take this thing in yet? Almost sounds like the lower intake gasket is blown. Wow sounds really weird. Let me know..Brian

 

An intake gasket gone should throw a lean code , not a misfire.

 

I am kinda new at these too. Would a head gasket send a lean code also? Just curious what the issue is. Future reference thing.