2003 Ranger won't stay running

I have a 2003 Ranger 4x4 4.0L it's been running rough. I've replaced the coil, plug wires, plugs, and fuel filter. I am chasing the check engine light problems. FYI the codes I'm getting are: P0301 cylinder 1 misfire, P0302 cylinder 2 misfire, P0303 cylinder 3 misfire, P0300 Random cylinder misfire, P0174 system too lean bank 2, P0171 system too lean bank 1, P2197 System too lean, and P2195 O2 Sensor stuck lean bank 1. I have reset the computer 2 times since I replaced the parts and the codes keep coming back. I've tried the fuel injecter cleaner in the gas, 3 bottles so far and I'm at my wits end. I'm thinking either the Idle Control Unit or Fuel Injecters next. Any thoughts????

I have a 2003 Ranger 4x4 4.0L it's been running rough. I've replaced the coil, plug wires, plugs, and fuel filter. I am chasing the check engine light problems. FYI the codes I'm getting are: P0301 cylinder 1 misfire, P0302 cylinder 2 misfire, P0303 cylinder 3 misfire, P0300 Random cylinder misfire, P0174 system too lean bank 2, P0171 system too lean bank 1, P2197 System too lean, and P2195 O2 Sensor stuck lean bank 1. I have reset the computer 2 times since I replaced the parts and the codes keep coming back. I've tried the fuel injecter cleaner in the gas, 3 bottles so far and I'm at my wits end. I'm thinking either the Idle Control Unit or Fuel Injecters next. Any thoughts????

My thoughts would be to check your fuel pressure, air leak central to both banks, and mass air flow sensor.

Thank you for the reply and the idea. Do you know how to check the mass air flow sensor? Also I have noticed a sound like it's got an air leak or seems like it's got a cough. I'll look into this further. Thanks again.

You said it sounds like an air leak. Vacuum leaks will cause lean codes, and are normally the cause of them. Unfortunately, the computers compensate for spraying brake cleaner (use something less flamable than ether) on newer vehicles, which means you have to be quick to hear the idle go up. If I were at work, I'd use a smoke machine on the intake system, but at home, you're stuck with feeling and hearing and spraying for leaks. I have seen in odd instances the IAC leak vacuum, not around the gasket but from the IAC itself. Lean codes are hard to diagnose, even when you have the right tools. You said trying cleaners and possibly replacing injectors and whatnot. You're wasting money. If it were an injector, only 1 cylinder would be missing, and you have a random multiple code, what are the chances that all 6 injectors went bad at the same time? Lets evaluate your codes here...thinking logically..the misfire codes can be caused by lean conditions, and the individual misfire codes don't mean much because of the random multiple misfire code. The O2 sensor code is that it is stuck lean, well, if you're running lean, then the sensor is right. So we are left with lean codes, for both banks. well, lean codes will cause all of these problems, so you need to be chasing the lean condition affecting ALL of the engine, which means vacuum leaks, possibly fuel pressure, but normally the computer will compensate by holding the injectors open longer, or a mass air flow issue. If I were you, I'd be looking for vacuum leaks. and don't count out the IAC.

Try spraying carb cleaner around the intake plenum and see if it changes your idle. Thats the plastic chamber that bolts to the intake manifold. I just had to replace my plenum seals and it fixed my problem. I chased my problem for a while also, egr, idle motor, etc. It only took about an hour and the seals are about 6 bucks. Be sure to clean the mating surfaces before bolting it back up. Not that hard of a job. Good luck.

Thank you for the reply and the idea. Do you know how to check the mass air flow sensor? Also I have noticed a sound like it's got an air leak or seems like it's got a cough. I'll look into this further. Thanks again.

Tim, you're on the right track if you hear an air leak. As the others have mentioned, you can use carb cleaner which is sprayed onto the area where the intake manifold and heads meet. If you hear a smoother or higher idle then you've found the leak. Some people also use propane or if you have a smoke machine, that would be the best option.

As far as the MAF sensor, you can use this link and that will point you in the right direction as far as the cleaning goes. I'm not sure about the operation of your MAF sensor. It could be the analog type as mentioned in the link, or it could be the frequency type. For the analog type, you could use a DMM or if it's frequency, you could measure it at different RPM's with a DMM if your meter has that function or with a O'scope. If you plan on keeping the truck and want to learn more it, you could get a subscription at www.alldatadiy.com (http://www.alldatadiy.com) at a very reasonable rate and has all the OEM information. Good luck with the repair and keep us posted of your results!

http://www.therangerstation.com/tech_library/CleanMAF.html

No doubt that a mass air flow sensor could cause this, but as my profile says, I am a ford master certified tech and even though I am young, I haven't seen many MAF sensors cause lean codes. If testing like those instructions say, just remember that those sensors are EXTREMELY delicate, and when out of thier housing, a drop of a few inches can destroy them.

Hello! To all of you. Sorry that I haven't talked to you guys in awhile. Job problems, as usual. I just wanted to thank you all for your wisdom and kind words. I found the issue to be a vacuum leak in the large rubber elbow in the front of the engine under the radiator hose. The covering on the radiator hose rubbed a soft spot in the elbow and it had a hole in it and was sucking air. After repairing it I erased the codes and only 2 came back. Lean on both banks. But it runs very well now and idols much better. When the warmer weather gets here and my job situation gets better I'll find and fix the code issues.
Thanks again.
Tim