Well i have a 2001 5.4 Triton Supercrew 4x4 with 190K and in the past month ive been experiencing some rough idling.

Yes i did use the search but nobody seems to have my problems exactly.

Well i noticed when it started getting colder (from 70+*-55* and under) that my truck when in PARK would have a rough idle. like it would be normal then drop off to real low idle and start fading in and out. like a sputter but just real casual like low to normal. Never showed the CEL though

It drives fine and everything. I cleaned my k&N air filter about a week ago and it really needed it so i thought that was it. a couple days later the check engine light came out. went and changed my oil (it was due) light still on. has been on ever since and idle still rough....

Is this rare to only be a problem in park and not in gear or while driving?
Any ideas?

 

What's the code?

 

idk. how do i check the code?

 

scan tool, autozone and places like that do it for free.

 

Go to AutoZone and have them read the codes with their scanner. They do it for free.

More than likely you fouled the Mass Airflow Sensor with oil from your K&N filter.

The slight miss could be due to aging plugs and coils.

 

i went to chane out my spark plugs awhile back and they looked brand new so i left them.

my o2's might need replaced though ive been thinking of doing them

 

With a 190,000 its time to do some cleaning if you haven't already. Clean the MAF, with MAF specific cleaner, don't touch it, just spray the cleaner on. Clean the throttle body. Possibly replace/clean the IAC. Check for vacuum leaks on the 90 degree elbow on the back of the intake, near the IAC. It's known for degrading and cracking. If it is idling rough in park, let it do it for a while, a code should show up.

 

He has a CEL, just doesn't know what it is yet. Need to know

 

Got the codes run. 300 & 171

 

A code P0300 may mean that one or more of the following has happened:

* Faulty spark plugs or wires
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector(s)
* Burned exhaust valve
* Faulty catalytic converter(s)
* Stuck/blocked EGR valve / passages
* Faulty camshaft position sensor
* Defective computer

Possible Solutions

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

P0171 OBD-II Trouble Code

Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1.

Note: This DTC is very similar to P0174, and in fact your vehicle may show both codes at the same time.
Symptoms

You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.
Causes

A code P0171 may mean that one or more of the following has happened:

* The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
* There could be a vacuum leak downstream of the MAF sensor.

Possible Solutions

Possible solutions include:

* In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
* Inspect all vacuum and PCV hoses, replace if necessary
* Check for a dirty fuel filter and proper fuel pressure

 

Prob guna clean my MAF sensor and change my o2's and sede if that does the trick. my 02's probly need changed anyways even if it doesnt fix it.

And what r1jester said i probly should also clean my throttle body and other engine compartments.

Is it ok to just spray the MAF sensor with brake cleaner?

 

I wouldnt, you have to find a good electrical cleaner that doesnt leave behind any residue. Or you can make it worse than what it is. I have used crc MAF cleaner but some recommend against it. Jbrew has a method he uses, maybe he can swing in.

 

ok hope he chimes in

 

Jbrew uses windex I think. I use crc no issues. Junk the K&n. I did, have it sitting in the box on a shelf in my garage. They dont filter as well as paper and when over oiled the get the maf funked up. I just bought a wix filter and plan on replacing it once a year.

 

CRC MAF cleaner is okay. Better than nothing and better than most. JBrew uses alcohol and a Q-tip, I don't recommend you touch the MAF with anything unless you know what you are doing and are experienced. It's too easy to break the fine wire. Just spray it and let it dry.

Don't change the O2 sensors yet. They look like they are doing their job.

The most common cause for a lean code is a vacuum leak - and the most common vacuum leak is the PCV elbow behind the intake manifold.