I have a 2002 ford ranger with a 3.0 6 cyl. Lost power last night. Throwing po171 po304 po305 po306 code thats a lean in bank 1 and 3 misfires al in the same bank. Cheched the plugs and the wires and colepack are only about a year old. Any ideas?

SOURCE: 1999windstar missing prob

check the pcv valve vacum lines for a leak a vacum leak will set 171 174 codes. lift the hood with engine running and listen for a air leak , check all vacum lines if no vacum leaks can be found then clean the mass air flow sensor by spraying carb cleaner directly on it for about 5 seconds. in other words take the air filter cover up and spray down the tube that leads to engine. shine a light down hose first and see if u can see the mass air flow sensor so u can get a direct hit

Dennis Mulford

• 1055 Answers
• Posted on Jan 24, 2009

SOURCE: 1999 Ford E250 van Rough running

complete tune up plugs wires distributoe cap and rotor

SOURCE: 1999 ford windstar 3.8 eng miss

remove the plenum take out injectors have them rebuilt change your plugs should clearup problem.  
ps if you have blowby problem could come back in a few months of driving.

SOURCE: 2000 astro with 4.3 new plugs

sounds like you may have a stuck closed poppet (fuel injector) inside your plenum. No fuel would cause misfire and a lean conditon. Also a vacuum leak in that cylinder would cause a misfire but yoyr spark plug would be fuel fouled.

SOURCE: WHAT ARE THESE 2 COMPUTER CODES FOR MY FORD RANGER

Description : The adaptive fuel Strategy continuously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit. Now that we have an Idea of what the codes mean , we need to narrow them down. More than likely the problem is causing both codes to set. Keeping this in mind, lets concentrate on Code PO1309. Of the possible causes listed above I see two Sensors that may throw up a lean code. I would look at the MAF Sensor first and then the Temp Sensor. You may find that if you remove the internal Sensor from the MAF Case that some degree has collected on the thin wire. If you find debree, use a Q-Tip to clean it. DO NOT USE CHEMICALS TO CLEAN IT. If no debree is found, try a Known Good MAF Sensor. Still no fix, move on to testing the rest of the Sensors on the list till you find the problem. Keep in mind that the check engine light will have to be cleared after you have fixed the problem.