I have a hard time getting he monitors to set on this car. I changed all 4 oxygen sensors and a MAF. Fixed any exhaust leak, did plugs, and the car appears to bever go into closed loop.

I get no codes and no CEL. I've been using elm327 and autoenginuity software scanners. No codes. I borrowed a friends VCM rotunda and that showed me a MAF code, therefore I swapped the MAF. Still same thing, when I monitor it as I drive it stays on Open Loop, when I go WOT it switches to Open Loop -due to driving conditions.

What else could be causing this?

 

when you say open loop what did you mean and can you use simple english to describe whats wrong with your car? ws it an idling issue or was the car misfiring? where are you from ?

 

He's from Chicago....

Open loop and closed loop relate to the EFI mode. Open loop is when the EFI runs on preset air/fuel maps based upon some sensor feedback. Closed loop is when other key sensors like the oxygen sensors provide feedback allowing for continuous variation of the air/fuel maps.

Modern EFI systems will move between open and closed loop depending on the driving conditions and the programming of the system.

It sounds like the OP is saying his never goes into closed loop mode when he expects it to and is looking for some troubleshooting advice.

I have no expertise in how the X300 ECU is programmed for open versus closed loop, but often engines run in closed loop at idle or low speed/load, going into open loop at high speed, WOT, etc as key sensors such as the O2 sensors can't react quickly enough so the ECU then references static air/fuel map tables.


....this is where some of the former mechanics or someone like XJREngineer(Andy) can help

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I figured it out. Borrowed my buddies VCM/IDS did adaptation for the o2 sensors, gas pedal and TPS and the car went into closed loop and passed all readiness monitors.