question on po 171 code 2003 Camry

This code can also indicate a bad O2 sensor. I recommend that a live data scan be performed, that should be able to trace it down before you get it inspected.

To get the CAT and EVAP monitors to set the gas gauge must be between one quarter and three quarters full. Once the gas gauge is within that range drive normally for a few days and the monitors will set. Hope that helps! Jim

Thank you for your replies, I will check on the O2 sensor after driving the car on the highway today for a bit. . Frustrating thing is that the car is driving fine ,

You're welcome. Glad to help! Jim

What engine is in this vehicle?

You might have a few pin holes ....leak.....upstream of that O2 sensor. Suggest you ck the exhaust system for leaks.

The CEL PO 171 is back on at 249 miles. , The engine is a 4 cylinder . I am searching for an honest shop in my area (Westchester NY) to look over the car, this could be something simple or hours in labor to determine the cause I do have a Toyota dealer near me but the service ratings online are very poor,

Any good independent shop should be able to track it down.

Ok.....seems we have Camry with some 280,000 miles with a CEL comes on and will most likely keep you from passing An emissions test. A vehicle this age and mileage.....do the easiest and cheapest thing first. Have someone put the car on a lift and inspect the exhaust system as noted above. If there are NO leaks upstream of the O2 sensors.....replace both O2 sensores.