[lori2qt4u]

Just bought a rebuilt motor for my 2006 chrysler touring 3.5L RWD automatic (magnum motor) and the mechanic finished installing it. Trouble codes P0031, P0037, P0051, P0057 have come up now. He claims he checked the wiring and still a problem. He told me to go ahead and take it, drive it around for a month and maybe the check engine light will turn off since sometimes you need to drive it a bit to clear everything out of the valves. I asked if he tried replacing the sensors from the old motor just to check it out, which he says he has. I'm afraid to drive it for fear that something might mess the motor up. Also, I was told it wastes a lot of gas that way. Any other options anyone before having to replace the sensors?

 

[Normgarry]

Just bought a rebuilt motor for my 2006 chrysler touring 3.5L RWD automatic (magnum motor) and the mechanic finished installing it. Trouble codes P0031, P0037, P0051, P0057 have come up now. He claims he checked the wiring and still a problem. He told me to go ahead and take it, drive it around for a month and maybe the check engine light will turn off since sometimes you need to drive it a bit to clear everything out of the valves. I asked if he tried replacing the sensors from the old motor just to check it out, which he says he has. I'm afraid to drive it for fear that something might mess the motor up. Also, I was told it wastes a lot of gas that way. Any other options anyone before having to replace the sensors?

I've had to replace two O2 sensors. In my car, the check engine light would come on when the car got low on fuel. Now - no problems. There's usually no way around it.

 

[Jdixon77]

I am in the same senario. Had a rebuilt engine put in a month ago, drove about 400 miles and now mil is on with p0031,p0037,p0051 and p0057. Codes will not clear. How do I check for voltage on the ASD output circuit? 2006 3.5 HO

 

[magnuman]

Welcome to the forum. As you may already know, these codes are all related to the Oxygen Sensors, specifically the heater circuits. Was anything else changed when the engine was.....like the PCM? It's a little strange that the problem is with both cylinder banks and, I assume there were no codes before the engine swap???? In any case, because of the nature of these codes, I think I'd check the grounds for the heater elements in the O2 Sensors. I believe they all use a common ground. There must also be ground straps from the chassis, to the exhaust system and also from the exhaust system to the engine.....I think it actually grounds from the exhaust system to the transmission though.....same difference. You may also want to hook up a quality diagnostic scanner and see if the heaters are working at all (they're obviously not though) and how long (if at all) it is taking for the fuel management system to switch from open loop to closed loop from a cold soaked (overnight) engine start. IIRC, it should take less than about 45 seconds for this to occur. If the heaters are not working properly, you'll end up with extremely rich mixture (black smoke), perhaps fouled spark plugs (random misfires), increased fuel consumption, and so on. Fix it ASAP to avoid further fuel management related problems. Worst case if run this way for a long period of time, the catalytic converters could get fouled. Then you'd be into another high dollar repair.

 

[Jdixon77]

Welcome to the forum. As you may already know, these codes are all related to the Oxygen Sensors, specifically the heater circuits. Was anything else changed when the engine was.....like the PCM? It's a little strange that the problem is with both cylinder banks and, I assume there were no codes before the engine swap???? In any case, because of the nature of these codes, I think I'd check the grounds for the heater elements in the O2 Sensors. I believe they all use a common ground. There must also be ground straps from the chassis, to the exhaust system and also from the exhaust system to the engine.....I think it actually grounds from the exhaust system to the transmission though.....same difference. You may also want to hook up a quality diagnostic scanner and see if the heaters are working at all (they're obviously not though) and how long (if at all) it is taking for the fuel management system to switch from open loop to closed loop from a cold soaked (overnight) engine start. IIRC, it should take less than about 45 seconds for this to occur. If the heaters are not working properly, you'll end up with extremely rich mixture (black smoke), perhaps fouled spark plugs (random misfires), increased fuel consumption, and so on. Fix it ASAP to avoid further fuel management related problems. Worst case if run this way for a long period of time, the catalytic converters could get fouled. Then you'd be into another high dollar repair.

 

[Jdixon77]

Nothing was changed except the engine and even tho it had a rod knocking the mil was not on. My son has driven 400 miles on the reman engine and its been fine. I found it weird that all four sensors were coding at once

 

[magnuman]

Clear the codes then and see if they come back.

 

[Jdixon77]

Clear the codes then and see if they come back.

I cleared them and they return immediately on start up

 

[magnuman]

Have you checked all the wiring and, especially the grounds and the grounding straps from the chassis to the exhaust system to the transmission?

 

[Jdixon77]

I haven’t had much time the past few days, that’s my task for tomorrow for sure