Mechanics

ENGINE CODE

2004 Lincoln LS

Engine Performance problem
2004 Lincoln LS 6 cyl Two Wheel Drive Automatic 94000 miles

My Lincoln LS check engine light is on. It has code P0408 catalyst efficiency low bank two. I am not sure what would be causing this. I have had to replace the coils on cylinders 4 and 5 due to misfire.
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Bullflyer
November 14, 2009.



P0408 isnt a cat code, its an EGR code...P0430 is the code that fits your question? What code do you actually have?


http://www.2carpros.com/forum/automotive_pictures/62217_P0408_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_P0430_1.jpg


If it is P0430 Then it could have been caused by the misfiring, check the cat for damage to the inside, or honeycomb bed. Rap on it and see if it rattles, if it does the bed has broken up. Heres two pictures of the cat and O2 sensors before and after low effeciency is when the rear sensor switches fast, like the front one, an efficent system switches slow and is almost flat on the rear sensor.


http://www.2carpros.com/forum/automotive_pictures/62217_P0430a_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_P0430b_High_1.jpg


If you have P0408 let me know, there are a few Tech bullitens on this...

Merlin2021
Nov 15, 2009.
Sorry, my mistake I have a PO430 code. I will check the catalyst. Thanks

Will it hurt to run it this way?

Tiny
Bullflyer
Nov 18, 2009.
Well cars dont heal themselves, but I would check the response on the sensor two, downstream of the cat (behind), it may be a sensor out of range. Other than that, it means the cat is dead anyway, so it means you wont pass your next inspection, if the cat isnt clogged, it wont hurt to drive it, but I couldnt say without looking at it. If you have any lean codes, fix it now, lean running engines can be damaged!

Merlin2021
Nov 18, 2009.