My 98 Ford E150 4.6 V8 with 98000 miles has codes 171 & 174 System lean banks 1 & 2. What are the possible causes? So far I have replaced the O2 sensors because they were due. Other posts I have read say vacuum leaks, low fuel pressure or maybe a clogged injector. I want to change the fuel filter next. Does it require special tools? I haven't been able to find a vacuum leak using propane, brake cleaner, and a hose to my ear. The van runs fine idles smooth and starts quickly. Should I have the fuel injectors flushed? I will appreciate any advice.
Mar 15, 2006 at 4:29 PM