P2195 after catalytic converter install…

[roybus14]

My 04 Expedition XLT 4.6 has 220k miles and just had the catalytic converter replaced with whole exhaust system.

Drove for a bit and got a solid service engine soon light on and I got a P2195 (1/1) Pending - O2 Sensor Signal Biased/Stuck Lean - Bank 1, Sensor 1.

MAF and air filter are brand new.

Got it home and turned on to my street and she just cut out. Drifted to the curb, stopped and started her back up and drove the 50-60 yards home no problem.

Didn’t get the P2195 code prior to it failing. Did have the fuel pump recently replaced and changed out the MAF and air filter.

What should I be checking for next? Bad O2 sensor, vacuum leak, fuel injector issues?

 

[SafariGoneWrong]

I replaced my passenger side exhaust manifold going on 2 years ago and took the opportunity to replace both #1 O2 sensors. The passenger side sensor is the most difficult to replace and get the connector on and off. I’d check that if you can—connector integrity first. Mine is an ‘06 5.4 3V but I imagine the location being cramped is similar…. If it’s stuck lean I’d imagine the PCM is going out of closed loop and using its map for fuel metering.

 

[roybus14]

I replaced my passenger side exhaust manifold going on 2 years ago and took the opportunity to replace both #1 O2 sensors. The passenger side sensor is the most difficult to replace and get the connector on and off. I’d check that if you can—connector integrity first. Mine is an ‘06 5.4 3V but I imagine the location being cramped is similar…. If it’s stuck lean I’d imagine the PCM is going out of closed loop and using its map for fuel metering.

Thanks SGW... One of the things I was going to do is replace the #1 sensor upstream on the the passenger side since my code reader is pinging that after each reset.....

But could the connector integrity be an issue if the catcv was replaced? Maybe not connected correctly???

Regards,

 

[SafariGoneWrong]

Going from memory, the wheel well liner has to be removed to get access. Can you get a visual on the sensor as is? I suppose it’s possible to get a bad sensor out of the box, maybe it’s an installation issue. I remember making the connection was much harder than disconnecting it, but the memory is fuzzy. I’d turn to FORScan Lite to see what all the sensors are doing.

 

[kep5niner]

FYI - you can access all of the O2 sensors, but removing the inner-fender / wheel well liner is necessary. However, that only takes exactly 5 minutes. Like an idiot, I’ve timed myself doing it. The trick is you just have to find all of the screws that secure the inner fender - some are hidden behind trim / body cladding. After you find them all the first time, you won’t forget where they’re hidden for the next time.

 

[kep5niner]

Reading over your original issue, I think the O2 sensor may be a symptom, but not the problem. Why did you have to replace the cat(s)? Physically clogged, as evidenced by a back pressure test? Guts gone? Or were they smoked from too much fuel being dumped into them? That could be for a multitude of reasons. Leaky intake manifold (thus other lean codes), vacuum issues, etc.

I’ve never heard of a bad O2 sensor killing the engine. May need to look at other potential issues. Good luck.

 

[SafariGoneWrong]

When all is well, the #1 sensors are constantly going back and forth from rich to lean based on the PCM varying the injector pulse width. The PCM added more fuel (a lot more) and did not see the O2 sensor respond. That means a lot of air is getting to the sensor (or it's bad, wiring, connection), but only on the #1 bank. You'd think there would be a driveability issue also. Could be a failed intake manifold; I'd think the #2 bank would be affected if it were a vacuum leak in one of the hoses or manifold ports. I always think first what changed, and that was the installation of an exhaust system. It would be good to see what your #2 O2 sensors are seeing and what #1 Bank 2 is doing. You didn't mention the cause for the exhaust system and new cats. Any preexisting conditions?

 

[roybus14]

The cat started rattling like pieces were broke off inside it is why it was replaced. And my shop did the whole exhaust system.

 

[roybus14]

Was the O2 sensor. They replaced it and all seems to be well now. No more codes, all points are green and both STFTs and LTFTs are within their normal ranges now….