brush99

About a month ago, my F150 started idling very rough and throwing a P0012 code which is 'Variable Camshaft Timing Over-retarded Bank 1'. I took it into the service center and they changed the oil because it had been 7000 miles and according to them, it was not even on the dipstick and 4 quarts low. I know, shame on me for not keeping an eye on my oil level but, there is was no visible sign of a leak and I get my oil changed regularly. Anyways, the oil change did the trick and the truck was running like a top (relatively speaking for an 11 year old vehicle with 130,000 miles) again. Also worth noting that when the truck was running rough my oil pressure gauges is never low.

Fast forward a month to yesterday when out of the blue, it starts running rough again and the Check Engine Light comes on. This time it is throwing the same P0012 code as well as a P0174 code which is 'System Too Lean Bank 2' I checked the oil which was fine. I parked it in the driveway overnight and when I tried to start it up this morning, it struggled to start. To me it sounded like it was not getting fuel at first but finally started up. It also said 'low oil pressure' while it was trying to turnover but I am 99% sure it has always said that when you go to start it and the engine does not turn over right away (i.e. if battery is going bad and cranks but does not turn over).

Some things I am going to try are replacing air filter, cleaning MAF and also changing out the fuel filter to try and address the P0174 code. I don't know that this will do anything to address the P0012 code but these items are due for replacement/maintenance so I figured I would try it first. While at AutoZone picking up parts I had them run the codes again to see if they had better information. Their machine suggests as a possible cause of the P0174 that the H02S21 (Heated Oxygen Sensor - Bank 2 Sensor 1) may be faulty. Any thoughts on that?

I am going to replace the VCT Solenoid in bank 1. I don't know this is the problem simply because it threw the same P0012 code when my oil was dirty/low but for $119 it is worth a try. Other than that, what are your thoughts on taking it in to get the fuel injectors cleaned as well as going ahead and changing the oil again even though it has only been about 800 miles since the last one?

MHOWELL34

Could have jumped time but that usually is p0345, try to clean some stuff and see if you can make it throw a different code.

vintageman

When I had the poo12 code, I took both vct solenoids out, cleaned them with throttle body cleaner, installed them in the opposite banks to see if code would follow. it did not but I think the code the returned as soon as I started it was saved in the memory. I cleared the code and months later, it still has not returned. Running your truck low and possibly with dirty oil may just have put garbage in the vct screens and they need to be cleaned. I would give that a shot prior to part replacement, unless you have the old style of solenoid and not the upgraded version. If so, then replace them both. Good luck.
Tom