I have a 92 Toyota Corolla 4A-FE. I took it for an emissions test and it failed. I installed new: air filter, spark plugs, PCV valve, fuel filter, O2 sensor, ran injector cleaner through it and also did an oil change just before.
I noticed that it was running lean when I changed the plugs. The timing is set to 10* as per the sticker under the hood. I listened to the injectors and they all seemed to be clacking or working. the spark plugs are the same as the ones listed in the manual (NGK).
I am wondering how to fix the Lean problem. Any help would be greatly appreciated.