Our 2004 tribute with 100K miles recently started stumbling at idle while stopped at traffic lights. A few days later the CEL came on. The codes are P0171 and P0174.

Any ideas about the cause?

Thanks,
Mike

 

Your codes are very similar to eachother, and both mean an oxygen sensor detected a "lean condition" in both Banks, ie too much O2 in the exhaust. They could be the result of a dirty/faulty MAF sensor or a vacuum leak.

Some possible solutions are to clean the MAF sensor using an automotive electrical cleaner, inspect/replace vacuum and PCV hoses, or check for a dirty fuel filter and fuel pressure.

For more ideas, other posts on here refer to recently tuned-up Tributes showing these codes; you can run a search for "0171" and find them.

 

Check the air intake tube from the air cleaner to the throttle body. I have a protege 5 and the code came up 2 times. I felt the bottom of the air tube to find this cracked in the bellows area. I see others are having this problems as well. I haven't found an aftermarket so I duct taped and pvc taped over it for now.

Jack