I have a 2006 s type 4.2 wont pass emission code p0101 came up they said maf , so I replaced air filter and cleaned maf sensor disconnected battery cable for a minute to reset drove about 60 miles and cel came back on ,do u think its vacuum leakes ,car runs good, when I start it up it idles up and down between .5 and 1 rpm for a 2 minutes then it smooths out at just below 1000 rpm , one time it stalled when I came to a stop ,but it started up and drove ok ,also transmission sometimes jerks when changing gears. I forgot to mention there is small leak under the driverside wheel maybe transmission leak the car has 105000 miles never spark plug change. I think that's it a lot to swallow uh.please help .

 

Hi Macke, I've moved your thread to the S Type tech section.

 

Grab JTIS / codes PDF and it has a list of all the known causes.

Inevitably they'll include bad sensor, wiring etc.

 

I thought all my information was entered if not where is the signature section. anyway I may have found my problem , I both the car with 45000 miles on it and I never changed the spark plugs,it has 105000 miles on it. doesn't the cel come on after certain miles intervals/ thank you

 

Only the diesel has a Service Due indicator - and doesn't seem very good, either.

I can't see it being plugs as they're good for 100K miles by the book so probably good for quite a lot more in actuality - but I'd change at the service figure anyway.

Bad plug(s) are almost guaranteed never to cause P0101 I reckon.

It really really is worth looking at the known causes stuff......

 

well where do start , p0101 says mass air flow I clean maf sensor and replaced air filter ,also unplugged maf sensor and car cut off. that mean sensor is ok right.

 

Nope, it means it can tell when it's not there at all. It's #1 suspect.

 

so u think its maf sensor I was told with the car running u unplug maf sensor and it cuts off its not the maf sensor, I also tried to start it with it unplugged and it started up and it cut off. is that true

 

Who told you that?

Why should it be true and if it is what does it prove? Very little.

It's no way to treat any modern car. They have OBD II and it's what you should be using unless you'd rather swap part and hope. I'd look at fuel trims, though you may well have a bad MAF.

 

I got that off you tube , I will go tomorrow and buy maf sensor ,if that doesn't work do I need anything while im there. thank you

 

I would recommend an OEM MAFS; aftermarket ones have a higher defect rate.

 

Well hell, if it came off the internet you know its the truth!