15 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHABS & PSM warning lights
Leading reported evidence
Replace mass air flow sensor
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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Discussions that performed work without a confirmed outcome
1
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Performed · outcome unconfirmed
I replaced the MAF after sensing a loss of performance at the top end.
Leading evidence: 'Replace mass air flow sensor' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'maf, especially if you have a k&n' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Clean ' car' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
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Suspected cause
I agree with James - most likely the MAF, especially if you have a K&N.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
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Suspected cause
Other possibilities are a dodgy brake light switch or ABS sensor, but if it happened under heavy acceleration, it is more likely the MAF.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
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Suggestion
Don't forget that sticking extraneous stuff up into the airflow will degrade your mpg, so don't compare your return with that from a 'clean' car.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
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Suggestion
I agree that cleaning never seems to last long, but I'm dubious of a video made by an oiled filter manufacturer which says the oil in the filter will not contaminate the MAF.
Combined work: Replace mass air flow sensor + Run bmc oiled air filter i
No successful repair reported for this finding.
0
Reported fixes
1
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that report an unsuccessful attempt
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Unsuccessful attempt
I replaced the MAF after sensing a loss of performance at the top end. Because I run a BMC oiled Air Filter I cleaned it first but that didn't fix the problem.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Unsuccessful attempt
Because I run a BMC oiled Air Filter I cleaned it first but that didn't fix the problem. I had none of the usual lights come on but definitely did the trick
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
15 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
911uk: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 1 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261027T020439Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Driving home last night, cam to a favourite stretch of open road and put my foot down, getting to about 5.5 -6000 rpm the abs & psm warning lights starting to flicker and then came on & stayed on until I got home. On turning the engine off & back on the lights stayed off & haven't driven it out again yet.
Any ideas? Found on Renntech that MAF could be a problem or air leak, anybody else had this?
Thanks Steve
The MAF is a possible culprit, do you run an after market air filter?
I replaced the MAF after sensing a loss of performance at the top end. Because I run a BMC oiled Air Filter I cleaned it first but that didn't fix the problem. I had none of the usual lights come on but definitely did the trick
Hope you get it sorted
J
Well a spirited drive on the way home tonight and the lights have stayed off so I'll have to see if it happens again. i have been toying with getting a new MAF as mine is only returning 21.8mpg on daily drives (mostly short journies) I can certainly get more like 30mpg on long motorway trips but Lloyd reckons his short commute was still returning higher than mine so I may give him a shout for a new one.
I'm currently using a cold air induction with a K & N filter by the way J.
I agree with James - most likely the MAF, especially if you have a K&N. You could try cleaning it - it might preserve it a bit longer.
Other possibilities are a dodgy brake light switch or ABS sensor, but if it happened under heavy acceleration, it is more likely the MAF.
Thanks Richard,
What's the best way of cleaning it? I have some Electrolube Ultrasolve solvent cleaner for electrical components, if I spray that onto the MAF wire, will that do the trick? I've read somewhere to try gently brushing it with solvent with a fine artist brush?
Where's GT4, our resident MAF cleaning expert?
Don't use anything with lube in it. A straight isopropyl alcohol spray is the best thing to use. Just spray loads of it into the opening and shake it out. Do this 2 or 3 times. It is a hot-film MAF, not like the older type hot-wire ones. I wouldn't put anything in the opening at all.
If it has done anywhere in the region of 50,000 miles, I would replace it anyway, as it is living on borrowed time.
HTH
No this is just made by Electrolube, doesn't contain lube it's methoxy proponol, cyclohexane etc for degreasing & ridding pcb's of flux etc, sounds like it would be perfect for it but don't want to knacker it without a replacement handy!
Cleaning a MAF is a waste of time, they should be replaced. They dont get affected by crap from the airintake its the silicone that is in the cicuitry that leaks from the casing down the sensor and prevents the MAF functioning properly, dispite contrary belief with regards to oiled filters and dirt contaminating them.
http://www.knfilters.com/maf/4MAFSensorVideo.htm
ahhh...so I take it that when I put the cold air induction kit in, washing the airbox and polishing it in silicone spray to make it nice and shiny & slippery may not have been the brightest idea then
Good news is that the lights have stayed off ever since that one time but I do think the MAF is probably ready to be replaced shortly as i feel my mpg could be a couple of miles better.
Whatever, I still love my car!!
Just a thought here.
I notice in your sig that you have a full aero kit?
Don't forget that sticking extraneous stuff up into the airflow will degrade your mpg, so don't compare your return with that from a 'clean' car.
I agree that cleaning never seems to last long, but I'm dubious of a video made by an oiled filter manufacturer which says the oil in the filter will not contaminate the MAF. You could easily find a dozen forum threads from users where over-oiling has.
ttshinykit - if you still have the original MAF in your car after 55k, then it's probably time for a change anyway.
MAF
My car has 60k on the original MAF.
So how do I know if it needs replacing? What would it cost?
When I had my K&N and remap done about 14k miles ago last year, it hunted a bit when starting but after a week driving has been fine ever since.
I like to keep my car tip top, is it worth changing because I have no perceived problem.
If it ain't broke, don't try to fix it. When it starts to go you will get problems like ttshinykit is having - psm/abs lights on heavy acceleration, etc. I just suggested he changed it, as it sounds to me like it's on the way out.
Before it starts playing up like that, it often gives a fault code in the DME control module. On RoW cars, like ours, it does not cause the CEL to come on, but on US cars it does. Generally, you will get a small loss in performance, which you won't notice, as it occurs over a long period of time. If you are concerned, get the codes read with a Porsche tester, and it will tell you.
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