Shop Lincoln Oxygen Sensors

Hello all, my friend has a 96 Lincoln Towncar and 3 codes came up on my scanner- PO420, PO171 and PO174 The PO420 has to do with Mass airflow sensor, and I believe I can remove it and clean it, but the other 2 I was wondering how many oxyen sensors are there and where are they located? Any help would be appreciated Thanks

Yes, cleaning the MAF on Fords will usually bring them back to life. I'm not at work now, so can't advise you on the 171 and 174 codes. Just because you come up with O2 codes doesn't neccessarily mean they are bad. There may be other concerns causing the O2s to set a code. The Lincoln will have two upstream O2s and at least one downstream. Now, if the codes are for heater circuits, 9 times out of 10, the O2 will need to be replaced, but...it could be a circuit problem (no voltage to the heater circuit). Good luck.

The P0420 does not have anything to do with the MAF. That code is for the converter operating below efficiency. The P0171 and P014 are for both banks of the engine running lean. Neither of those codes indicate MAF or O2 sensor. The MAF may or may not have anything to do with the 171 and 174. If you cure the reason for running lean and erase the codes, you may not have the 420 any more either. Lean conditions can be vacuum leak, low fuel pressure, plugged fuel filter, air leak after MAF in the air inlet tube. Plus a few more items.

Thanks for your quick responses, I guess I will have to investigate further as to what's going on.

I cleaned the mass airflow sensor reinstalled it and am waiting to hear back from my friend on which of any codes show up. Thanks for the information. As for the PO420, I'ii wait to see

Keep us informed. And thanks for the update.

He told me the check engine light came back on, so I scanned it and the only code was PO420. I guess I solved the PO171&PO174 code, because I cleaned the mass airflow sensor. Now I'm unsure of what to do about the PO420.Any suggestions on this? could it be catalytic converter or oxygen sensors? Thanks

95% of the time the converter is the cause of the P0420 code. Something caused the converter to fail. As our resident emission specialist says "Converters do not die, they are murdered."

Thanks so much for the info, I will keep you informed on the progress!

I have a 2003 Lincoln LS V-8 with 127,000 miles. The "check engine" light came on and I took it to a local Ford dealer. Diagnostics showed that #3 cylinder was mis-firing and I was told it needs a new coil pack and 2 upper oxygen sensors. I was quoted $748 to get this done. I presently don't have that kind of money laying around, what's the risk in putting off this fix until I can get some money saved? I would need to drive the car until I get the money as it is my only means of transportation.

Gee Tom, thanks for your help, you sound like my dad!

A bad misfire will let raw fuel wash cylinder walls, bad o2 sensors will let the convertors fry along with the raw fuel dumping . NOW your talking some real money!