Engine Performance problem
1997 Ford F-150 V8 Four Wheel Drive Automatic 204000 miles
Ok- My truck kicked the infamous p0171 codes and gave missfire codes on cyl 1 and suffered a major power loss though it has 35" tires with 4.10 gears. I replaced every plug/wire, new coilpack (though it was just a year old) replaced 02 sensors, new MAF sensor, new IAC sensor, new pcv valve, checked hoses for vacuum leaks, new fuel filter, ran seafoam through vacuum line from brake booster to smoke out the system. Still no improvement. I took it to the dealer who diagnosed that everything looked acceptable except cyl 1 failed the leakdown test. Suggested a new motor since the rings were probably shot. I had a new Jasper put in- idled better but still no power on hills/hard acceleration. I decided to go with catalytic converters. Temp tested between the 2 banks and bank 1 (pass side) was extremely hotter. Replaced both sides (all 4 converters) to be safe. Still no power improvement though I had no check engine light. One day later my CEL came on. Hooked it up and it's the same p0171 code saying Sytem Lean on Bank 1. I'm bank at the beginning though my bank account is almost $6,000 lighter. I guess Fuel delivery is my next route.
Sunday, October 3rd, 2010 AT 4:09 PM