Engine running rough
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Engine running rough
Getting codes 0171, 0174. Replaced both top oxygen sensors, tps, and maf. Replacing the tps seemed to improve idle and performance. Nothing changed with maf. Still running a bit rough at idle and still getting codes.
04 f150 heritage xl
04 f150 heritage xl
Lead Driver
Joined: Sep 2006
Posts: 7,907
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Your codes listed tells the story.
The long term fuel tables are shifted rich setting the codes and causing hot rough low speed running and stalling at idle.
Leave the Ox sensors alone. they are only reporting the trouble..
Find / fix the vacuum leak causing the table shifts..
The long term fuel tables are shifted rich setting the codes and causing hot rough low speed running and stalling at idle.
Leave the Ox sensors alone. they are only reporting the trouble..
Find / fix the vacuum leak causing the table shifts..
Tuned
Joined: Jul 2019
Posts: 311
Likes: 19
What engine? I just fixed mine and should have listened to posters like Bluegrass for example as they were spot on. If it's a V8, check the elbow that comes off the intake near the throttle body if I'm not mistaken. If it's a V6 like mine, you're very likely looking at islolator bolts and intake gaskets, which was my issue. Another possibilty could be the PCV Valve grommet may not be holding the valve in properly which I orginally thought my issue was as mine wasn't installed in the valve cover at all when I looked the engine bay over (the second time).
As mentioned by Bluegrass, the O2 sensors are working fine and have their own code for when they failed or at least my 01 Silverado did. Check over all vacuum lines and fuel filter. Test the fuel pressure as well but be prepared for an intake gasket job. Hope this helps.
As mentioned by Bluegrass, the O2 sensors are working fine and have their own code for when they failed or at least my 01 Silverado did. Check over all vacuum lines and fuel filter. Test the fuel pressure as well but be prepared for an intake gasket job. Hope this helps.
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RayandTracy
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