Folks, I see that this subject has been covered before but its new to me. I hope I don't draw the ire of you regular contributors as I ask some dumb questions. And ask opinions. My 2009 2.2 has 230,000 miles on it. I'm at a crossroad as to whether to walk away from it or try to keep it alive. I am a senior with limited income and a paid off car but it actually does not fully suit my needs anymore, other than it is running and gets me around and no payments. In the past 8 months or so, I have put on new tires, replaced ac compressor at a professional shop, had the auto transmission completely rebuilt at a cost of $2900, new battery......so I have some recent money invested but still.......a pickup truck would suit me better right now.
ISSUE.....car runs fine, has good acceleration, cruises nicely on freeway, shifts great, bla bla bla. But.......after cruising at freeway speed for any distance, when I come to a stop, the car idles really bad as if only on 2 cylinders. More frequently now, it will stall if I don't put in neutral and keep rpms over 1000. I do have o2 sensor codes for stuck on lean, but my fuel trims look fine. I don't think the O2 sensor would cause the rough idle but ? Additionally, twice in recent weeks, the car ecu has completely freaked out when starting on driveway. The other day when I went to start car, the dash lit up like a Christmas tree, all gages flat, no power steering, a padlock emblem displayed ?.....I eventually got everything off by repeated resets with the ignition on, five steps on gas pedal manuever. And then I drove the car 200 miles with no issue except the rough idle after freeway cruising.
I am tempted to replace the O2 sensor #2, and do plugs and coils, if I was to continue CPR on this car.

 

I think it’s worth saving, how old is the battery? Have you had it load tested? Under 12.3 volts is a dead battery.
Have you checked the under hood fuse box are the halves tight? Are the fuses and relays fully seated?
Have you every cleaned the throttle body and MAF sensor?
How old are the spark plugs?
would you please post the actual codes .
this could be something simple.

 

How could the trims be good if the O2 sensors are stuck low? The #1 sensor controls the Air/Fuel mixture. The #2 sensor monitors the health of the cat; if it is not functioning the computer assumes the worst and messes with everything in an attempt to not to cause pollution.

The only reason the "lock & key" shows up is the electrical system is faulty as in dead battery or bad connections. Any voltage reading below 12.6 indicates a dying/dead battery.

 

Thanks oldblue......codes are 0137 and 2270, both pending and cel on. Battery is only a few months old. Voltage idling is 14,5 at cm and 14.2 at obd. I have not cleaned the throttle body or maf. Spark plugs probably ancient. Not changed in my ownership of last 90,000 miles. I will check the fuse box and relays.

 

Here’s some reading for you, note the causes and possible solutions

https://www.obd-codes.com/p0137

and that other code,

https://www.obd-codes.com/p2270

Note both are possibly from an exhaust leak. And possibly low fuel pump pressure, then there’s the low voltage.
It is plausible the new battery is not charging fully or not connected tightly, I would have it load tested, at the battery.

 

Voltage running just means the alternator is running.
Plugs last 100,000 with the CORRECT AC/Delco.
Assuming those codes start with P, either the fuse is blown, the wires are melted on the exhaust or the #2 sensor is bad. If you replace it don't use Bosch. With all your othe symptoms, I would look at wires shorting as a prime suspect.

 

Thanks Don. I'm basing my fuel trim comment on my experience with troubleshooting lean codes on other cars. According to my obd, torque app.....the ltft and stft are hovering near 0 at idle with slight correction fluctuations, but nothing like my other car with radical lean code that was always exceeding +20 and triggering cel.

I will go check my battery terminals for good connections

 

Point of fact, you mentioned the transmission was removed and rebuilt, then reinstalled, then that could be the event which caused the problem, the O2 sensor wires could have been damaged then .

 

Its possible the tranny shop damaged something, but the symptoms did not immediately appear after the rebuild. However, and a bit off topic, a few weeks after this rebuild, my car almost caught on fire with trans fluid blowing all over the pipe. After towing back to tranny shop, they acknowledged they found a blown seal and attributed it to faulty torque converter. They then supposedly took it all apart again and replaced the faulty torque converter which I had assumed was part of the original rebuild. It becomes a pissing contest as you know. Did they try to avoid the expense of torque converter in the first place or did they mishandle the job or did they truly receive a bad torque converter? Who knows? At any rate, I suppose you can realize my weariness at putting a lot more money into the car, other than it is a paid for vehicle.

 

I suspect the fire caused hidden damage to wires and since the fuse box and computers are directly above the torque converter ......