So long story. The truck information is as follows: 1997 Ford Ranger, 4.0L, 4x4, odometer reads roughly 245k miles, head gasket blew years ago because my sister didn't put coolant in it, me and my neighbor (a mechanic) swapped out original motor with a 98 motor with similar milage.
Now that we got all the background let's get into the current issue. About a month ago my truck out of the blue started to have a rough idle then shortly after started to surge. Checked for vacuum leaks and couldn't find any so I went to the local parts store and had them put the scanner on it. The truck threw codes for Bank 2 sensor 1 O2 sensor and one for sensor 2 (downstream) O2 sensor. Replaced them and the truck ran at about 80% so I replaced MAF sensor and the truck ran great. I thought I reset the codes at that point but I could be wrong. Fast forward a month truck was running fine when I left home. 30 minutes after turning it off I go to start it and it started surging wanted to die in drive but if I could get it to accelerate it would run fine until I took my foot off the accelerator. Limped it to the parts store and scanner shows the following codes.
P0174 System too lean Bank 2
Secondary DTCs
P1443 Evaporative Emission Control System Purge Valve Malfunction
P0135 O2 heater circuit (Bank 1, Sensor 1)
P0153 O2 Circuit slow response (Bank 2, Sensor 1)
P1130 Lack of HO2S11 Switches Fuel trim at limits
P1131 Lack of of HO2S11 Switches sensor indicates lean
P1151 Lack of HO2S11 Switches sensor indicates lean.
long list..... Thing is I know at least half of those Secondary DTCs were present as Primaries a month ago so that's why I'm second guessing if I reset the codes.
I returned my Bank 2 Sensor 1 which I replaced a month ago and put a new one on thinking maybe the replacement was faulty but the truck is running the same.
Last thing, my battery gauge started showing low (at the exact same time this problem occured) although it's a new battery and alternator tests fine. I was going to replace the negative terminal tomorrow since it had a small crack at the base of it but otherwise the connection is fine.
Thank you for any help and thanks for taking the time to read this very lengthy message.

 

Check your intake systems any leaks around your filter or hose such as clamps can affect your maf sensor and your ecm may be trying to compensate. Intake manifold bolts too make sure nothing is loose and it's all torqued down to spec.
Also your egr valve may be something to look into since you are throwing emissions codes, egr deals with emissions recirculations bullshit and although not common they can go bad.
Double check your vacuum lines also , especially if you have those stupid pulse vacuum lock hubs , I'm sure the engineers at Ford are trying really hard to forget about that stupid idea, but yeah if it's 4x4 check the hubs too you have a vacuum line going to both front hubs that may be bad. Those are known to go bad

although also not common you may need to replace your catalytic converters, (should have 2 on that thing) they could be fouled up causing back pressure and the computer can read that also and try and compensate, which may also explain all the o2 sensor codes.hold your hand to the tailpipe and see if the pressure coming out seems reasonable.

 

is the engine block grounded to the chassis? alternator grounded? get eyes between firewall and top back of intake manifold . is the pcv valve clean? the line from around maf to oil fill is secure or oil cap and dipstick tight? any of those will stress the crankshaft out. i chased that po174 code for months. honestly the intake manifold gasket setup is trash and id put money on it or that you are simply overheating . torsion bar lift or even jack the truck up a little high will split that gasket seal. otherwise make sure that thing is full of coolant and burp the heater core. unplug negative terminal to reset ecu and do the idle RELEARN steps . my 98 4.0 ohv has little over 300,000 miles and no check engine lights. surging issue is probably dirty fuel filter .