My S type is an 03 with 85,000km. Finally got my Autoenginuity software and found that my mil light was for P0105 - Manifold Absolute Pressure (MAP) sensor issue and not an oxygen sensor as I had suspected. Has anyone had an issue with this sensor? Is it easy to change? (that is if one can get one).

 

Is the car a V-6 or V-8 or an STR?? It must be rare, I have never heard of one going out. I wonder if its not pointing to a different problem??
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The car is a 4.2 V8 regular (not Supercharged). JTIS lists

Intake manifold air leak (loose or missing
component)
MAP Sensor to ECM circuit(s) fault
MAP Sensor failure
Throttle adaption fault (check throttle position
voltage at Ignition ON)

as causes. If I can find the tech stuff about the MAP sensor readings, I can check the voltages and what the MAP is reading. The MIL stays on for several cycles then goes off, only to return 2-3 days later.
I think it may be a dirty censor as I know I have had at least 1 big backfire that may have carbonated the inlet manifold!!

 

Don't be too keen to just replace the MAP. But equally, I don't know if it can be cleaned (I guess not). I've also no idea what they cost!

Which AE did you buy - just the basic or with jag-enhancements?

How did you come to have a backfire and do you believe it's fully fixed?

 

How and why did this happen? If true it could have easily ruptured the diaphragm in the sensor.

 

I thought it was - perhaps my memory's gone. I do remember last year after a particularly cold night I had to crank the engine lots, stop and start again and I thought it backfired then. I know on occasion I have had lots of smoke out the exhaust, having to crank a lot on cold mornings (after I forget to plug in the block heater), but thats just downstream ignition.
I read on several other car forum sites that cleaning the MAP (a bit like the MAF) makes a difference and can cure performance problems.
I think a MAP for an 03 Jag is about $165 (not a jaguar price) and it is only 2 bolts at the back of the engine if one can get to it.
I have the full AE monte - basic + jag extensions.

 

Er... since when was a MAP like a MAF???? Usual MAF is a hot-wire sensor with intake air passing by. MAP is a pressure sensor, quite delicate. If either's damaged, no cleaning will repair them. You can clean a dirty MAF and you may fix it. I'd expect to replace a damaged MAP, end of story. But if Real_Tech has another take on it, do as he says!

Your AE should let you monitor MAP. If it's damaged expect to see meaningless readings

As you've that P code already.... what do you expect to see?

 

Didn't mean that MAP & MAF were the same sort of sensors, just that you can gently clean them.
I get the code alright but what gets me is the on and off nature of the MIL being set. If the sensor has gone bad, surely the MIL would be on permanently not clear itself after however many cycles then reappear x startups later? I'll check the voltages of the MAP and TPS and possible leaks or wire problems.
Thanks for your comments

 

A dirty map is possible. It's not like a mass air though. The map sensor on the Jag has tiny little passages allowing the engine vacuum to the sensing element. It can be clogged with oil that is in the intake and has started to carbon on the sensor. More common with high miles. I can't comment on cleaning, never tried it because it is such a pain to get to, always replace them because I wouldn't want to do it twice if I could avoid it(v8 only, v6 easy).

 

AE lets you monitor MAP (among sooooo many others). Why not graph it at idle, at fast revs, and if need be as you drive and look for weird values?

Also, figure out what the KOEO (engine off) reading should be where you live and check that it's right.

 

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