Hi all,
I recently found this forum, and as luck would have it, I just had a problem with my recently purchased '04 XJ8 (67K miles)in the form of a "CEL" coming on a couple of days ago. I read the codes and got a P0105 (MAP sensor) and P1111 (generic diagnostic code?). As far as I can tell, the P0105 is either a bad MAP sensor, a problem with the wiring to the sensor or an intake leak. I was wondering though, if an intake leak were big enough to trip a MAP sensor code, wouldn't you also get an oxygen sensor code of some sort? Before I go and spend $100+ on a MAP sensor, does anyone have any other ideas or know if these sensors are prone to failure?
Thanks!

 

My take is: 1st, are there any symptoms? 2nd, if there are no symptoms, turn off the light and see if it comes back, 3rd, if it comes back, check the harness, run the pinout tests if you can (IuseAlldata.com for the tests), 4th, if all else fails, replace the sensor. This may be the cheapest part on the car, but with a bad MAP sensor, your mixture will be in question, eventually causing other problems.

 

I should have mentioned that your question aobut the O2 sensor is on target, if the MAP sensor is really bad, the O2 sensor could get involved, but maybe down the road aways. The ECU will try to manage around it for awhile if it's not too bad. To get to the bottom of it, you need to put the car on a real time scanner and look at the fuel trims to see if the MAP is really causing problems. The MAF is the major player with the MAP being the backstop to the system, so it can take some time for the problem to show up.

 

it usually just needs a good engine internal cleaner.. too much carbon builds up around the sensor.. only if the code comes back then i wud replace the sensor.. not to fun to replace.. but i never seen one.. that came back after a good carbon cleaning. there is a bulletin on this

 

Well, a good cleaning sounds better than having to replace the sensor...especially since I have subsequently discovered you have to remove the plastic intake manifold to get to the MAP sensor! Does anyone know if an intake tract cleaning can be accomplished at home (i.e.: use a can of some type of miracle cleaner "tee'd" into the intake manifold w/engine at idle) or do I have to take the car to the dealer for this service?
Thank you!

 

i wud take it to the dealer.. they have some that the fuel is disabled and the car runs only on the chemical for about 15 minutes.. also cleans out injectors and exhaust system.. also helps with the gas mileage..

 

BG 44K. Dealers use it.

 

One thing you will find on the MAP sensor, it is only used to provide diagnostics for the EGR valve. Of course it can still cause a light, but it is of no consequence until you have an EGR problem.