RepairPal is your advocate for car care advice and guidance

Q: Emission Symbol Warning Light on 2005 Lincoln Aviator

Please advise if anyone has had an issue with the emission symbol appearing for 2005 Lincoln Aviator. The symbol just appeared 2 days ago. Thank you.
Get a Repair Estimate
Guaranteed by certified locations nationwide. Learn more
RepairPal estimates are guaranteed at over 1,700 quality certified locations nationwide. Learn more
The check engine light can come on for dozens and dozens of reasons. A diagnosis must be performed to determine what codes may be stored for failure in the engine's processor, and then the codes must be interpreted to determine the actual failure.

P0420 is a bank one catalyst efficiency code. On a 2003 Aviator, often times it can be cleared up with engine calibration updates. It can also be a result of faulty sensor readings - there is a sensor before the converter and after the converter...and if the readings of the sensors do not differ before or after the converter, then the computer feels like the catalyst is not functioning efficiently. Most times the sensor end up good...and the converter ends up faulty. Testing will confirm, though, what the problem really is.
Hopefullly you will get a raesonable diagnosis that will set you in the right direction.

Good luck to both of you!
Hi 2005 Aviator, I have a 2003 Aviator and my emmission light was on as well. I failed inspection and the printout they gave me was a code:PO420 the OBDII and what exactly is that code, I have yet to get an accurate answer. 1place said it was my Converter, to which I disagree because that code is for a few other things also like resetting a sensor, it could be the gas cap, or even it can be the cheap gas I put in it is when the Emission Light came on Eission Light came on. So when u find the problem, can u let me know as well. I will do the same for you when I get the problem with my Emmission
Hello Anonymous,

I am taking my vehicle in for diagnostic check tomorrow, I will let you know what the results are. By the way, I have always used the correct grade of gasoline as recommended by the manufacturer always 91 or above (Premium, Sucks!).

01/03/2011- Sorry for the delay, the problem was located and needed PCV hose total cost $206.50 parts and labor which is covered under warranty.
Didn't find what you were looking for?