I have a 2000 Toyota Corolla that the check engine light came on and every time I go to advance auto parts to check what it is saying system to leanI get them to take it off and it come on again.I decided it was time to change my spark plugs and airfilter. It still came on again. I went to take it off. Guess what? It came on again.I am thinking it could be something wrong with the oxygen sensor or the catalytic converter(which is not easy nor cheap to replace!!!).Anyway, it costs $85 to know EXACTLY what's wrong with it at the Toyota DEALERSHIP?!! should I take it in? I really don't totally trust these people because they usually try to milk your pocket and get you to change things you don't need to change!
You already spent money on spark plugs and an airfilter that did not help. Many things could cause a lean condition, not necessarily a bad O2 sensor.
A Lean mix can mean 2 thing one not enough air or fuel., Need to get a code scanner from your local auto parts store and see what code its pulling, then go from there.. Imo you have cover'd the spark plugs and filter and did you do a intake cleaning? if not do that you just spray it into the Butterfly after the air tube..Changing the fuel filter isn't a bad thing to do it will keep the fuel injector clean and running great. Once you have don't all the basic tune up maintenance and your still getting the same code then IMO your getting a bad injector and sould be looking for and miss fire code and it will tell you what cylinder. hope this helps...
I dont know of any dealership that rips you off. What you mean to say is you dont want to spend the 85 dollars on a diagnosis by a professional because you are scared to know how much it really costs to fix. You can continue going to your professionals at Advanced and have the light turned off or you can go to a Professional and pay the proper diagnostic fee for a PROPER diagnosis. A lean code is an idication of a vacuum leak, intake leak, low fuel pressure, etc.... Why would you change spark plugs and an air filter for that code?
I guess your system too lean is: P0171 System Too Lean Fuel Side. To be sure, better get the code from the Advance Auto Parts, or otherwise get the code read at a dealer. System too lean is in the engine control part, has nothing to do with the catalyst converter, which is a part of the emission control. System too lean means the air/fuel ratio is not correct, here is too much air in the A/F mix. But I am afraid you need to get the exact code before trying to make any diagnose or repair. The Toyota dealer I work with charge $49.95 for check engine light scan. But if you can get the code for free from a auto parts store, you do not have to go to a dealer. A car will surely cost some money for maintenance. System too lean is rather a common problem. Replace air filter and spark plugs will not fix this problem. But they are part of regular maintenance, and should be replaced at intervals. Before you get the exact code, I can not make any suggestions. Good luck.
try a new fuel filter if it is restricted it will lean the fuel mixture out
