hi guys, so I recently bought a 2004 xj8 (yayyyy) and I'm in love with it. But I have a few gripes. my check engine light has come on twice, the first time it was only on for an hour, but more recently it stayed on long enough for me to get the codes out of it, p0105 and p1111. My car is still under warranty and furthermore (thank you massachusetts) has to pass state inspection which means the dealer must correct the problem. I know its a MAP sensor malfunction fault but I'm not informed enough to know whether I should ask them to replace the sensor, or if there is an actual underlying problem not just a bad sensor.
Also I feel like the first ten minutes of my commute at a steady 50 mph the engine and transmission are not working together nicely. theres a surging thats apparent on the tach too. 100rpm's or so. AND finally, from top gear to a passing gear i hear like, a squawk/OOP/URK sound. I've read that this can be remedied-- I just want to go to the dealer with a nice little list of how I want these problems addressed so that they don't try and cut corners or waste my time with possible fixes that don't usually pan out. I'd appreciate ANY help or advice or input or anything. haha thanks guys!

 

Replace the sensor with the new updated 1, the old sensor buld stick down into the air stream and get oil vapor on it. The new style has a retracted sensor bulb and doesnt suffer the same fate. While you might clean it, itll just do the same thing and the sensor is a pia to change going by feel and mirror to do it since its hidden on the back of the intake.....

 

There was also a recall on the early X350s for a gearbox control reprogramme. I get the slight hunting under the circumstances you describe until the engine has warmed up. Only thing is the circumstances are rare for me due to distances and speed limits. My car is the XJ6 with the 3 litre Ford V6 engine, not your V8.

 

The surge could also be the torque converter.