Code

I am attempting to diagnose an issue with my younger brother's 00' Escort ZX2 48,000 Miles don't know the engine size though.

Engine idles rough
SES came on recently. Scanned engine at Autozone: Code P0171 - Lean

I am curious if there is a standard culprit before we start going down the troubleshooting list.

MAF Sensor
Vacum Leak
Bad Fuel Pump
Spark Pugs and Wires
Air Filter
Any others?

I have a feeling he is going to take it to a Ford stealership and let them commit highway robbery on him :).

I can't control him though. He can make his own decisions at 20 :).

Thanks for all your help.


Jesse

The place to start is to clean the MAF sensor if possible. They can get dirty especially if you are using a K+N or other oiled air filter. If that does not work the next step would be to check the injector to see if it is working properly. If the injector is clogged it could cause a lean condition. You may also want to check the front O2 sensor since it may be giving false readings.

Hose to PCV valve was cracked, causing the valve to clog. Fixed and all is well.