1998 Mercury Mystique 4 cyl Two Wheel Drive Automatic 145000 miles
The code P0171 on my reader says " system too lean bank 1". After failing smog, I realized I would have to fix the check engine code instead of just clearing it for the test.
I failed the test due to NO being too high at 15 mph. Max for my car is about 450 and mine was at 611. I just barely passed at the 25 mph speed.
The following is what I have already replaced within the last week or so, which was all done to both bring down emmisions and hopefully remove the check engine light. Cleared codes after many of these repairs to see if the CIL would come back, so it has been on and off many times.
-added hose clamp to both ends of the breather hose(one end had only a zip tie, the other end at the engine had no clamp at all)
-replaced BOTH 02 sensors (upper and lower, realize now that was a waste)
-replaced the mass airflow sensor
-checked the egr valve (this was done by a mechanic, who said it was fine)
-new fuel filter
-checked fuel pressure and pressure regulator, which were within normal psi
-changed engine oil and filter
-replaced spark plugs
-replaced air filter and breather filter
-added a 16oz bottle of Lucas fuel system cleaner
I attempted to use the " soapy water" method to check for any hose leaks, but I did not find any issues, and was not really sure what I was doing or sure where to locate all the hoses that I might need to check.
Tuesday, May 18th, 2010 AT 11:17 AM