ford f150 4.2l v6 code p0174

I need a little help on how to fix this code. According to the web p0174 is running lean (it's bank 2 on this engine). It originally had several codes which cleared when I changed the battery (obviously) but I replaced all the fuel injectors because #2 injector was bad(confirmed by the mechanic the guy I bought the truck from used). after that all codes stayed clear. Then I had a couple exhaust leaks fixed yesterday and driving home the service engine soon light came back on and I pulled this code with my scanner. I don't see how fixing the exhaust would cause this code, do you? Is there a solution?

You'll probably have to reset the fuel adaptive tables to clear this code. It probably has ran bad for so long the tables skewed themselves to "fix" the problem and now that it's fixed, it's "broken".

• O2 sensor on that bank (if it has 2) could be going bad.

• The exhaust work caused something to leak on that side

• Intake leak on that side. Possibly at the injectors that were just replaced or some where on the runners or at the intake manifold.

Can you run a Key On Engine Running test? That might tell you that one cylinder is offending.

In the fleet i used to work on aIl the 4.2 engines 04 and prior all ended up getting upper and lower intake manifold gaskets due to 0174.

But before you go in to that, check the O2 sensor for the offending side then (if you don't have a good scanner) unplug the battery for 10 min to get the KAM to reset and the adaptive fuel tables will relearn.

EDIT; if you can get ahold of a smoke machine that will definitely help as well, have had EGR tubes go bad causing a lean, lastly check the collector by the exit side of the manifold, they love to crack.

Ranger50 wrote: You'll probably have to reset the fuel adaptive tables to clear this code. It probably has ran bad for so long the tables skewed themselves to "fix" the problem and now that it's fixed, it's "broken".

How would you do that? I've had to do that with some of the industrial engines that I work with for the same reason, and its a PITA and requires a laptop, special cable and wonky program.

Awesome. As luck would have it I ran some gumout through the vacuum port and thats how I found the exhaust leaks in the first place. Everything else was sealed up tight apparently because there was no smoke coming from anywhere else. The previous owner also replaced the intake gaskets chasing other problems. I'll remove the battery cables for 10 minutes and check the o2 sensor at the same time. Thanks guys!

Last thing as well, if the code comes right back after the reset you have a hard leak somewhere, it should stay out for a drive cycle (about 30-50mi or a certain number of key cycles, don't remember how many lol) and if it does come back within that time frame you have a slight leak somewhere.

Good luck and keep us updated.