Trucks been non-op past 6 or so years. Tried inj. cleaner. Checked connectors. Generally seems to run o.k. but still sometimes gets a dirty inj. Don't have a emissions manual or breakout box. Any way to check o-2 sensor with ohm meter?
Ford Q&AAsk Your Question
1990 Ford Bronco Question: Keep getting code 42 on KOER test. Changed o-2 sensor. Shows always rich.
Answer #1G. T. Service Center (4071 Answers) , Stephenville, TX - (254) 638-3236ProfessorG October 13, 2013, 16:29Master
Think you have more problems then an o2 sensor. Leaky injectors/pressure regulator. Trying to remember, Warm up engine - test the gry/lt-blu wire and ground. Idle should be 0.1-0.9v, increase engine speed voltage should increase and decrease as rpms drop. If it doesn't work as stated it's probably bad.
ReplyR.J.Magellan, October 13, 2013, 17:13Rookie
Thanks,I'll''give it a try.
Answer #2pushrod October 13, 2013, 16:55Master
Full size Bronco? If so which engine?
ReplyR.J.Magellan, October 13, 2013, 17:20Rookie
Yeah, I thought that info was there. It's a full size Bronco with a 4.9 L 6,5 speed former Forest service vehicle with 85,000 miles.
Replypushrod, October 13, 2013, 17:58Master
Same injector giving the trouble every time? These engines had some connector problem at the injectors. Did you change the fuel filter? How much old gas is in the tank? Don't worry with the code just yet!
ReplyR.J.Magellan, October 13, 2013, 18:53Rookie
Yeah. I changed the fuel filter and the #5 fuel inj. was dumping raw fuel but then cleaned up. I changed it anyway but didn't help.
Answer #3Greg's Orange Auto (12984 Answers) , Orange, CA - (714) 361-9386globalhelper October 14, 2013, 06:00Master
AGREE WITH #1