Check engine light is on for code P0174 bank 2?

This is caused by an engine misfire causing oxygen the be pushed through the exhaust giving you the code.

I would start with a good tune up and throttle bore service. Here are guides to get you started:

https://www.2carpros.com/articles/how-to-tune-up-a-car-engine

and

https://www.2carpros.com/articles/throttle-actuator-service

Please run down these guides and report back.

Cheers

I had the same problem. I tuned the truck up the problem is gone.

bank 1 PO171 and bank 2 PO174

I have seen this problem before it was the MAF sensor fixed it. Here is a guide to help you step by step with instructions in the diagrams below to show you how on your car.

https://www.2carpros.com/articles/how-to-replace-a-mass-air-flow-sensor-maf

Please run down this guide and report back.

What does this mean. My F150 has been having issues in the past of stalling 2 minutes after starting and driving off (it did sit 4 days in garage). I got down to the first stop sign and the truck died I started and halfway to the next stop sign it died again. I started again and then once I put it in drive it stalled (twice this happened). I drove it home in reverse and three hours later started it and it was fine all the way to the dealer ship. This happened 2 times in the past 6 months. I've taken it in the ford dealership and they ran a diagnostic and said everything looks fine even the fuel pressure. NOW its been 1 month since the last incident and today my engine light came on out of the blue, the truck runs just fine. I checked the code and "it says P0174 system too lean" could this be related to the stalling. What would you do at this point?

Codes 171 and 174 usually indicate a vacuum leak. Sometimes the computer can conpensate for the leak and sometimes it can't creating a stall. Check all the vacuum hases coming off the intake manifold looking for a roted, split or cracked hose connection.

I checked for cracks or holes didn't see any but did see a hole in the PCV line can this cause it?

Sure can, I would replace the hose and then clear the codes to see what happens.

Codes P0171 and P0174 returning. Replaced MAF sensor and fuel psi.ok

A vacuum leak can cause these codes please check this guide out to help find it.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Truck listed above is an HD supercharged.
While stopped and idling for a period of 2 minutes or more the truck begins to run rough and the check engine light comes on. Once I accelerate, the truck runs fine until stopped for another 2 minutes or so. The check engine light will clear once the battery is disconnected, but will return once idling for a period.
Codes given are p0171 and p0174; system lean on bank 1 and 2.
Actions: fuel pump replaced (needed it), IAC, ERG, PCV, mass air meter, air filter, replaced vacuum lines that were faulty, spark plugs and coil packs done., o2 sensors replace today. Engine light comes back on after a short drive, idle goes to heck after about 2 to 3 minutes of idle running.
Help please. Only thing left I didn’t touch was intake gasket.

I think your hunch is right, Intake gaskets! Easiest way to verify this is to monitor the O2s11 and O2s21 sensor data while spraying the intake where it bolts down along the edges. If the voltage spikes to near one volt you have verified intake gasket leak!

BMDouble, thanks, will get on that first daylight.

possible soultions for trouble codes P0171 & P0174

It sounds like a vacuum leak to me. THe most common problem is a vacuum leak behind the throttle body (near the IAC). It is a vacuum hose that is aprox 3/8" and has a 90 degree bend in it. The hoses dry rot there and cause leaks.

Check that and let me know what you find. Also, check for other vacuum leaks (broken, dryrotted, disconnected hoses).

Joe

in a 2002 ford f150 4.2 6 cyl,we are getting a 174 code indicating bank 2 is running lean. could this be cause by the O2 sensor, maf or pcv vale being clogged. Please help as we are getting too many answers as to why this code keeps coming up once we have cleared it.

That's because there are dozens of causes for a lean code. The surprising thing is that you are not also getting a PO171 for the other bank. I have found that on Fords it's nearly always caused by a sever vacuum leak, usually from one of the main rubber vacuum lines

originally(2 wks ago) we did get the PO171, but it has since cleared by disconnecting the neg term on the battery and not returned.

my engine has a hesitation when I accelerate. I get the code PO174. what is this?

Check/clean or replace the MAF sensor ! 41) Continuous Memory DTC P0171, P0172, P0174 Or P0175: Fuel System At Corrected Fuel Trim DTCs P0171, P0172, P0174 and P0175 indicate a problem when adaptive fuel strategy senses a lean or rich condition beyond the minimum or maximum calibrated limit. Possible causes for these faults are: Fuel System Excessive fuel pressure, leaking or contaminated fuel injectors, leaking fuel pressure regulator, low fuel pressure or engine running out of fuel or vapory recovery system fault. Induction System Air leaks after MAF sensor, air intake system obstructions, vacuum leaks, PCV system or improperly seated engine oil dipstick. EGR System Leaking gasket, stuck EGR valve or leaking diaphragm or EVR. Engine Mechanical Engine oil overfilled, cam timing, cylinder compression or exhaust leaks before or near HO2S. Inspect engine for obvious defects in specified systems. Repair as necessary

My truck has many miles but has NEVER caused me problems. The check engine light came on but I assumed it was because it was close to 200,000 at the time. Now, in the last month, I have had to get it hooked up to a diagnostic machine 5 times and the check engine light gets "triggered" and comes back on. I have had the 02 sensors changed & its still showing p0171 & p0174. When it idles it starts to act like it is going to die and just barely stays cranked. I had another mechanic hook it up & he says that the 02 sensors are fine, so what are my other options to try & repair?

These ARE lean codes, you have a plastic manifold, try this.
You may have a vacuum leak, get a can of spray gumout, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs! If that doesnt do it, you may need a new idle air control valve, it's bolted to the throttlebody

use to set about 200 miles or so now less than 50.idle sounds like a deisel rattling valves.sets very fast if put under load.found dry roted hose to brake booster replaced no codes 2 weeks later setting less than 50 miles.cant find any vacuum leaks.poor milage.under load every now and then about 6 monthes it will set P0171.

P0171,P0174 codes are from vacuum leaks, low fuel pressure, mass air flow bad or pcv valve. i suggest this guide to see other possibilities.

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers


Roy