What is your question?
Struggling here... here's as much information as I can recall.
2006 ford freestar 4.2L 240000km
Initially I received an engine misfire code for cylinder 2. I ended up then replacing all the spark plugs and the wiring, as it was original. Every since then I have been receiving idling issues with the odd engine code.
After this replacement, I received p0171. Concerned, I ended up taking out all the oxygen sensors and cleaned them overnight in gasoline. Received the same code, replaced bank 1 sensor 1.
P0171 came back. Cleaned MAF/IAT sensor, repaired vacuum leak on EGR valve and EVAP system, replaced fuel filter. Removed injectors and cleaned them externally. Cleaned throttle body, idle air control valve. Removed catalytic converters and soaked in cleaning vinegar, rinsed and reinstalled. Filled exhaust flex pipe cracks with crack sealant. Two bottles of cleaner in fuel tank. Ran two bottles of cleaner through the intake system.
Latest code and only code now is p2195. Still runs rough but now it seems to backfire a lot and when check the temperatures of the CATs, bank 1 is quite a bit cooler than bank 2. Removed wiring from Cyl 3, no change in engine idling. Installed 3 and removed 2, no change in engine idling. Reinstalled 2 and removed 1, engine ends up running smooth at idle. Coil pack resistances all within tolerances. Cyl 1 spark plug black and wet...
What the heck should I try next?? I am not sure how I can remove a spark plug and the engine runs better... and the other two don't change the issue, tells me 2 and 3 are bad?
I am stumped. I haven't got a good code scanner to check fuel trims or a fuel gauge to check fuel pressure unfortunately.
What makes this problem better or worse?
Engine under load/acceleration. Better when spark plug 1 is disconnected.
How long has your 2006 Ford Freestar had this problem?
Three weeks
Thanks for the assistance. I can't tell if the PCV line is bad or not due to the added protection they put on it, but I did grab one from a scrap yard for free and threw it on there. No change. Too late now, but also replaced the fuel injectors with junk yard ones. Cleaned with a makeshift cleaning tool. I'd be curious if 6 is a problem, when I look at the CATs, bank one shakes a lot more than bank 2. I'll try another vacuum test, I could find anything wrong but maybe things have changed. Do you think an exhaust leak on the bank 1 manifold or at the CAT could be a cause? I wonder if when I reinstalled it, that it didn't sit right. Also, in case someone screwed up, if I received plugs for a 3.9 instead of a 4.2, could that cause similar concerns?
I took some video of the vacuum readings, acceleration while parked, etc. If you want to see what I am looking at. https://youtu.be/tBLa2jHTOjk
I watched the video, and the vacuum readings look perfectly fine. Is that with the coil pulled on cylinder 1, or installed on cylinder 1? Air leaking at the exhaust will lower exhaust temperatures by venting thermal energy outside of the system. I do hear what you are saying with better running conditions at higher RPM, and I wonder if that is the key to the whole issue. If disconnecting it or accelerating smooths the issue out, plus running without ignition on that cylinder gives you oil in the cylinder, it seems that a blowby condition is present, or if ignition of the A/F mixture in that cylinder is pumping into oil passages between the block and head. Piston 1 at TDC, leakdown test on that cylinder will show if these is the issue or even possible. Compression test on cylinder 1 (of course you would just do all of them) will be good info, should be done, but will not take the place of the leakdown test. When you're doing the leakdown, I would expect most to hear the air running from the oil dipstick tube or fill cap, though you may not leak at all.