I KEEP GETTING CODES PO171 AND PO174, BANK 1 AND BANK 2 LEAN. SO FAR I HAVE SPRAYED CARB. CEANER ALL OVER ENGINE AND INTAKE TO CHECK FOR VACUUM LEAKS, RAN SEA FOAM THROUGH FUEL, OIL, AND INTAKE, REPLACED O2 SENSORS, SPARK PLUGS, MASS AIR FLOW SENSOR, FUEL FILTER, AND THE IDLE AIR CONTROL VALVE. AFTER RESETING THE CODES I GET ABOUT 50 - 60 MILES AND THEY ARE BACK. PLEASE HELP.
I have 98 explorer im getting same codes ive worked on cars all my life I havent replaced anything but my fuel filter so far on the explorer and that wasnt it.I know people tell you to replace all that other stuff,but if you know cars and how the stuff works thats on a car then you can fix anything with out people telling you;you need to buy this and then this and there just fishing when the dont know there as* and whole in the ground.Im going to replace my lower and upper intake seals like he says above.At least theres one more smart one out there and not someone that thinks they know it all like people that work in the parts places and some dealers.
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Re: 1998 FORD EXPLORER SPORT 4X2 4.0 OHV
Unless you monitor the fuel trims while spraying the intake there is no way to see if there is leaking seals. these seal leaks are common especially in cold weather. I would recommend replacing them if they were never changed especially with high mileage
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Both codes mean a lean condition on the engine (P0171 for Bank 1 and P0174 for Bank 2). This is almost always because of a vacuum leak. Check all vacuum lines and vacuum operated equipment (EGR, brake booster, fuel pressure regulator, etc) for leaks. It could also be the intake manifold gasket. Use a spray bottle with soapy water to try to isolate the leak if you cannot hear the leak.
These two codes mean the same thing - the engine is running too lean. P0171 is for bank 1 and P0174 is for bank 2. This almost certainly means that you have a vacuum leak somewhere on the engine as it is detected in both banks. (If it were only in one bank, it may be a fuel injector or other problem.)
Inspect all vacuum hoses on the engine for aging/cracks/broken connectors/etc. Check the large vacuum hose going to the power brake assist servo. Check any servos or actuators that use vacuum for problems with ruptured diaphragms, such as for the EGR or fuel pressure regulator, etc.
As with most codes that the ECM generates, these are symptoms. There is very little one-to-one relationship between a code and a specific component/sensor/actuator. You have to evaluate the symptom and find what may be causing that problem.
Lean bank 1 and bank 2 , and throttle actuator system fault. Check reason for lean codes 1st, vacuum leak(s), air inlet boot and hoses, or low fuel pressure / clogged filter. Repair as needed then clear codes and recheck .
first PO171 o2 bank 1 s1 lean PO174 o2 bank2 lean PO401 cyl 1 misfire when an engine misfires the oxygen sensor will read the oxygen from that cyl sensor doesnt read fuel so every misfire is a air pump to diagnose we have to fix misfire first check the coil wires and plugs for cyl 1 use spray bottle with water run engine hot at idle spray wires with water if enging runs rough shakes or stalls then replace the wires dont spray with to much water if the wires are real bad you may not be able to restart engine
try this first once fix misfire clear codes and drive it
Check for engine vacuum leaks, use a can of carburetor spray and spray around the top of the engine, pay close attention to the intake manifold, if there is a leak the engine will speed up a little, also the MAF may be defective, cleaning it does not always fix the issue, which is the heated sensor wire no sending the correct signal. My knowledge base? Ford certified Master electronics technician.