hey guys I have a 97 f150 4.6. lately I have been having some issues with my idling and acceleration. my check engine light came on a few eels ago and the codes were

P0171FUEL INJECTION SYSTEM TOO LEAN BANK 1
PO174 FUEL INJECTION SYSTEM TOO LEAN BANK 2
P1506 IDOL AIR CONTROL OVERSPEED ERROR

I was recommended to change my IAC and MAF since a faulty MAF can trigger both lean bank 1 and 2 and i also replaced the IAC. The truck still has the same problem and same codes. I also had a leak in the line connected to my PCV valve and i fixed that and it helped a little bit but the truck still shakes violently sometimes when sitting at red lights or putting git into reverse after starting it up. Also when I stomp on it, ya know to get out into traffic, it isn't firing right and makes a kinda missing type bubbly noise like everything isn't firing like it is supposed to. Im tired of putting so much cash into the truck and the guys at auto zone, well they try their hardest.

 

You simply have an air leak that needs to be detected.
The 171/176 codes confirm it.
The 1506 is idle RPM out of spec caused by the excess air. This code likely will clear when the air leak is repaired.
Thing is you don't go on recommendations but trouble shoot and repair the fault. This is why diagnostic codes are provided.
Otherwise you spend and hassle without repairing for the problem.
Good luck.

 

Okay, so I fixed the air leak but the truck still shudders and shakes whilst idling. However they are not as violent as they were before. I just got back from getting the codes that were previously on it cleared off so i am interested to see if there are any changes when (if) they pop back up.

 

Its good that you're monitoring for tripped the codes.
It would appear that you still have a vacuum leak /leaks or a misfire.
It maybe necessary to go to a place with a more in depth scanner that can show the actual data of the sensors when it is acting up. Scanners from those big box auto parts stores tend to be just a scanner to read general codes.

If you already changed the IAC and MAF, Then next thing to do would be to change the spark plugs unless they are relatively new as well. Then go and recheck to make sure that you don't have one loose, re-torque to 28 ft/lbs

 

My plugs are wires are relatively new ( 5 months) I had a bad misfire before that on cylinder 2, we changed the coil packs but that didn't help at all and luckily I was able to swap them for new plugs and wires. It ran fine for about a month and then it would miss every once and while but would not throw a code. The misfire is odd. Sometimes it runs like a charm but more recently it has been struggling. Once I get past about 2,000 rpm I can hear it not firing right and i basically have no power to get up to speed or pass the person going 15 under the speed limit in the fast lane.