[345_300c]

Hello,

I just picked up a 2006 Chrysler 300C with the 5.7L Hemi for a steal, knowing that it had an unidentified "misfire" problem. Now that I have it home, the car seems to be able to run, and is mechanically excellent.

The first time you start up after a full night "cold soak", the car will run for maybe 10-20 seconds, before bogging down and shutting off. The ESP, ABS, Mr. Squiggles and CEL are all on immediately.

The second time you start it up, the car can idle almost forever, and is very smooth and quiet. If you attempt to drive, however, the car is stuck in limp home mode. (This is accompanied by the P0501 code.) Eventually, the car will bog down and stall at idle.

Every start attempt past this point will just bog down almost immediately and stall. Once the car reaches temperature, codes P1128 and P1129 appear.

Consistently:
P0031
P0037
P0051
P0057
Intermittently:
P1128
P1129
P0501
P0300
U0100

Any ideas as to what this could be? My car is obviously undrivable in this state, and very unsafe. Please, any help is so greatly appreciated.

 

[DGO]

P0031, P0037, P0051, P0057 are all Lambda sensor related. Either wiring or you have some bad sensors. Might be a place to start

 

[magnuman]

I agree with DGO. The O2 Sensors or wiring are probably in need of replacement. The P0128 and P0129 are also related to the O2 Sensors/ heater codes. You also have a loss of communication problem with the PCM, a random misfire code and speed sensor code.. A couple things to start with are to put a quality diagnostic scanner on it, one that can read the O2 Sensor voltages and crosscounts. These O2 related codes will also adversely affect your fuel trims, so they'll be out of whack too. The random misfire code is probably a result of the O2 issues. The lost communication issue could be related, but more than likely is a battery and/or connection problem. The speed sensor issue is probably unrelated and should be addressed after making the engine run properly. Depending on what the scanner says, I'd probably start by doing a compression check, installing new spark plugs and, if indicated, new O2 Sensors. Check all the O2 wiring and connections from the O2's to the PCM first though. How many miles are on the vehicle and is there any recent maintenance history available to you? If it has more than 100K on it and the O2's look like they've never been touched, I'd probably just install new ones. I'd also use the OEM brand, NTK (made by NGK), as they seem to work the best. Personally, I've had problems similar to your P0128-129 ones when I installed new Bosch sensors. Good luck and please keep us posted on your findings.

 

[DGO]

Agree with magnuman. I wouldn't be surprised if the speed sensor, ESP, ABS problem is a bad sensor/tone ring but get it running properly first.

Also at that age you'll need to check the transmission oil quality and level (there's an o ring poblem in early boxes). But again one for another day

 

[magnuman]

I am guessing that it has a lot of miles on it and/or hasn't been properly maintained for a considerable amount of time. O2's normally go bad slowly like spark plugs so, unless there's a wiring or PCM issue, these conditions could have been deteriorating over a fair amount of time. If I didn't have any maintenance records and it were mine, I'd be going over everything, a little at a time as needed. This is what I did when I bought my 06 300C SRT8 from my Grandson. Fortunately, no one ever really messed with it and everything was original and untouched. It appeared that only the minimum amount of maintenance had been done, and then only when it absolutely needed it. I spent about a year, off and on (and way too much $$$$), getting it up to speed and now I'd trust going anywhere. IMO, no substitute for timely, proactive maintenance and upkeep. Nothing I hate worse than a vehicle breaking down, especially if away from home.