Hopefully I'm posting into the correct place..?
The check engine light on my 05'TC went on a few days ago now the car idles rough and dies. I went to see 3 different car docs but none of them had software for the 05 model. I also stopped at Autozone as they are famous for their OBDIIs. No luck there either as all of them(3 different units) ended up giving some linking error. I was stuck going to the dealership.
$140 for a check. They pulled out code P2197, also told me it was o2 sensor 1 bank 1 to be faulting(called sensor#21). Also gave me $350 estimate for the repair which I declined.
I went back to the autozone store and bought the desired sensor(Bosch 15717) worth $50 and then took the car straight to my mechanic. He replaced it and when I pulled the car out of the shop I realized that there was no difference from before. My next step was to double-check with the store and my mechanic that they sold and installed the right part. Both were positive.
I just got home and went online, googled 4 that OBD code and found out this nice Ford-support forum. There are 2 other threads related to the P2197. In both of them I found that this same code stays for: Bank 2 Sensor 1 running lean!!!!! Totally the opposite one.
I just checked the Motorcrafts' OBD System Operation Manual and it also shows P2197 - "lack of switching, sensor indicates lean, Bank 2!!!!!
WTF???
Would there be any way for e to find if the dealer's service dept. is playing with me or if that particular code means any different for my towncar? Any follow up is greatly appreciated, any suggestions are welcome.
Thanks in advance for any help.
Tod

 

Welcome to FTE!
Shouldn't that car still be under warranty?
That code doesn't necessarily point to the problem. Remember that a rich misfire can lead to a lean reading there, since it doesn't read gas in the exhaust, just oxygen. Is that the only code coming out of the computer?
Other things to check might be-
Spark plugs, coils, fuel injectors, and possibly the mass-air sensor.

 

Thanks, nice to be here!
no, warranty expired a while ago, already have 70k on that puppy. Anyways, that's the only code the dealer came up with. I had the car checked at several other places and on all test it showed up some "linking error", don't know what does it have to do with it, maybe a software issue on their OBDs. I changed the fuel filter for starters but that didn't help either. I was also told that after swapping o2 sensors I should give it about 100 miles for reset before I make any major conclusions.....I hope they were correct!
And again, thanks for the reply, I'll keep ya all posted on this.
Tod

 

This is bank 2 sensor 1. Upstream sensor on driver's side. Correct sensor, wrong description reported.

Starting in 2004, Ford's onboard computer systems were converted to CAN-protocol communications. Older OBD-II scanners cannot support this protocol. An inexpensive CAN-protocol code reader (note I didn't say scan tool) is available from Wal-Mart for under $100. Made by EQUUS.

See TSB 4-17-4 on this site. It contains comprehensive instructions for diagnosing this concern.

Personally, I think it's most likely a vacuum leak.... "Lean" codes are almost never due to the O2 sensor.

Steve

 

Hey Steve, are you saying that i was sort of fooled by the dealership techs? Cause that's exactly what I found about that code, was reading all over the net last night. I also noticed my mechanic put the car on the lift and did change the sensor that was on the driver's side underneath. So probably he had figured it out right, I hope.
Tod

 

Probably not. My guess is that either there was a misunderstanding one one part or that the tech inadvertently misspoke. It's easy to mix up.

Since you specifically gave contrary code descriptions (correct sensor description but wrong bank) in your original post, I'll just lay it off to a miscommunication or a misunderstanding.

Based on all your descriptions, you should be looking for a vacuum leak....

Steve

 

Ok, I took the car for a ride today and the CEL went off after some 50 miles. good enough for a start of my day! But then, about 3 hrs later, after the engine warmed up, it started idling rough again!!! A couple of seconds after I come to a stop at a traffic light lets say, the engine just dies...
Now, Steve, you suspected that there is a vacuum leak. Where should I look for it? i was planning to take the car for a 500 miles trip on the weekend. Do you think that is a good idea?
Thanks again.
Tod

 

update: As suggested I had my mechanic check thoroughly for vacuum leaks, couldn't find anything. Two other mechanics said that they need to swap the idle-control....and they were pretty sure it was bad, so I asked him to check on that too,...well it works fine!
Both the air and fuel filters were replaced with new ones. I've been running it(the town car) with premium gasoline ever since that occurred. Maybe the mass-air filter?...who knows?!
I just read another thread suggesting for decarbonization as a cure after replacing bad o2 sensors. OK, but the car was driven for about 10k miles with the "bad" sensor and now it has a total of 70k. Is it possible that an engine with this amount of mileage is already due for a decarbonization and what does it have to do with o2 sensors?
I'm really really stuck here. Any follow-ups are very welcome. I'm still looking to find the light in the tunnel. Thanks everyone.
Tod.