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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed · Original poster
I have checked the large rubber boots on each side of the plenum, they are in position and well seated
Leading evidence: 'Check large rubber boots' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'components while the car is idling' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check connections marked red' (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 performed work without a confirmed outcome
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.
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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed · Original poster
I left the mahle paper filter and put the most recent MAF back which I cleaned before reassembly
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 performed work without a confirmed outcome
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.
Replace small 11*2.5 o-ring and made a paper gasket
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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 performed work without a confirmed outcome
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.
Performed · outcome unconfirmed · Original poster
I therefore changed the small 11*2.5 O-ring and made a paper gasket to improve the plastic/plastic seal
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.
Suggestion
Since you have a 996.1 check the rubber "bellows" below the AOS to see if it has failed, also do a manometer test on the AOS to see if the diaphragm has failed....these are two very common sources of massive air/vacuum leaks on 996.1 engines..
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
components while the car is idling
No successful repair reported for this finding.
0
Identified cause
1
Suspected cause
0
Reported fixes
Read evidence and context
Discussions that suspect a cause
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.
Suspected cause
Obviously, the smoke machine is �the best� test, but all that is really needed is a can of carb cleaner sprayed around the suspect components while the car is idling.
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.
26 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
� I had a kn filter in the original air box, I put a standard filter back > no improvement the fault P0103 returns after a few km
first, i'm french, so sorry for my english
so I just installed an ipd plenum + 82mm gt3 TB
I have a stainless steel top gear manifold, 200cc cat and muffler.
new engine (partial block 4 years ago / about 20m km) and (or not) kn filter in the original air box
so after installation throttle reset... before 1st start
1st start, idle not stable but no fault, 1st drive, approximately 50km no fault the rides
after I had the faults:
P0103: Factory Fault Code 115 = Mass Air Flow Sensor = Above Limit
P1504: factory fault code 410 = Throttle lift box, emergency air position = implausible signal
if I clear the faults and don't reset the TB, I just have the P0103 fault coming back.
I tried several things:
� I had a kn filter in the original air box, I put a standard filter back > no improvement the fault P0103 returns after a few km
� with the standard filter I tried 2 MAF > no improvement the fault P0103 returns after a few km (1 MAF have 3 years old and 15000km, 1 spare MAF have 9 years old and 50000km, 1 MAF is installed on a friend's car and works perfectly)
I left the mahle paper filter and put the most recent MAF back which I cleaned before reassembly
now after 200km the idle is more stable but i still have the fault(s)when it run
it works well (very well well!!!) better....
Any ideas?
otherwise I continue to drive / erase the faults and maybe it will get better....
because the MAF is faulty because it receives too much air but it's true...
OP - Check the connections marked red. Check for gap between tb and ipd plenum. Check the plenum on both banks to make sure no air gaps. A smoke check done yet? When I do stuff with the throttle body, plenum, vacuum lines, I pull out my handy-dandy $50 smoke machine. I�ve spent way too much time chasing vacuum/air leaks before I got smart and purchased the smoker.
hi
this morning I drove for 30km, the psm and abs faults appeared after 25km
here are the values i got
after start with no fault
during engine warm-up without faults
after 30km ride with faults P0103 and P1504
after 30km ride ,with no fault ( fault cleared)
I don't have a smoke machine but this afternoon I'm going to check everything for possible leaks
The RKAT values show that you have a massive vacuum/air leak...the DME is having to add a lot of fuel just to keep the engine running....
Since you just installed a new center plenum check the big rubber boots at each side of the plenum, you could have a boot that is out of position. You may have to R&R it again to ensure proper installation..
If you don't find anything then a smoke test is in order..
I disassembled, checked, reassembled
1er start with no reset of TB
cold
during the temperature rise , idle is stable without and with AC
when at temperature , i stop to do a reset of TB
at start-up the idle is very unstable, but I no longer have the P1504 fault after TB reset
idle is stable with AC
after a few minutes the idle starts to be more stable at idle without AC
I don't have time to go and try the car for a few kilometers to see if it improves, I will do it tomorrow morning
but already a good point, I no longer have the P1504 fault
RKAT will ALWAYS go to 0.00 after clearing fault codes....that is the starting point...
It should not move very far from this starting point unless there is a problem.....which you have....
ok thanks
i have a massive vacuum/air leak
I have checked the large rubber boots on each side of the plenum, they are in position and well seated
I also paid attention to the 2 hole for depression that it is not hidden by the plenum
Otherwise I haven't touched anything else.
Or did I have the leak before? but would I have had one or more fault?
I'm going to disassemble everything completely
I will try to find a smoke machine
Where do you get the smoke in?
Since you have a 996.1 check the rubber "bellows" below the AOS to see if it has failed, also do a manometer test on the AOS to see if the diaphragm has failed....these are two very common sources of massive air/vacuum leaks on 996.1 engines..
AOS is new ( 2month and 2000km) , i take a genuine and i changed vent line AOS/plenum and Oring for vent bank2
and i had no problem before change plenum and TB ( but i don't do test my RKAT value after AOS change)
I would bet its the rubber plunum couplers. Its always the cause of these air leaks after a plenum install. Everyone swears they r in correctly but they r crooked. Get an inspection mirror or endoscope camera and inspect the back side.
There is also a small plastic vacuum hose that connects somewhere behind the throttle body (I don�t remember exactly where - I think it�s to the intake plenum or runner right behind the right side of the throttle body� it�s been a few years since I did mine) it�s possible this has become disconnected or cracked�
Today I disassembled / reassembled everything (plenum and resonance tube) when reassembling I made sure that the sleeves were in place.
i controle everithing with inspection miror
vaccum of resonance tube is ok
vaccum in 2 sleeve's plenum is ok , I see them well exceeded between the plenum and the intake manifold when passing the mirror in the plenum
I just had time to start and warm up the engine but it already seems better
I no longer have the fault P1504 : factory fault code 410 = Throttle jacking unit, emergency air position = signal implausible , after recalibration throttle body.
Idle is more stable.
I took values (FRA are identical 0.99%)
it looks like i still have a leak ?
Like I have manyfold, 200cc sports cat and silencers from top gear uk, , it could not force to inject more gasoline because less braked on the exhaust?
RKAT must be at 0 even with modifications to the engine?
I made a smoke machine, I receive the oil tomorrow and I will do the smoke test on Thursday.
Tomorrow I'm going to drive a few kilometers with the engine warm to see what's going on.
thanks for your help
Get some miles on it now and see what happens. U can pull the ground off the battery for a couple minutes and it will clear all the old saved info. That may help the adaptations to look better now that u hopefully have the leaks sealed.
It's better but it is still adding a bunch of fuel to compensate for air leaks/ lean condition...
When you smoke test it, looks for leaks around the power brake booster hose to intake and the oil fill tube also, these are two more places that are common to leak. Air/vacuum leaks are one of the biggest problems of poor running and poor fuel trims for 996 cars..
Your RKAT is better than it was before, but +/- 0.36ms is the MAXIMUM before it starts setting fault codes...Preferably as close to +/- 0.00 as possible...
ok, I'm going to focus on these 2 parts,
in addition these 2 parts have never been replaced and my car is 22 years old so the plastics have had time to to heat up and harden / break
Obviously, the smoke machine is �the best� test, but all that is really needed is a can of carb cleaner sprayed around the suspect components while the car is idling. If there is a vacuum leak the carb cleaner (or other volatile substance) will be drawn through the leak and into the intake system which will cause the idle to increase�
investigations are progressing
this morning I did 40km and no psm+abs fault, no fault code detected
I did not take the values from RKAT
the baby oil has not yet arrived I did a test with brake cleaner, as I do not have a start pilot
by spraying towards the brake vacuum line the engine speed varied. I therefore changed the small 11*2.5 O-ring and made a paper gasket to improve the plastic/plastic seal
I did the test by unscrewing the oil cap, it is hard to unscrew and I hear a loud suction noise.
if the oil filler tube was cracked that would do it too?
I bought an o'ring for the oil filler tube, I think that in any case I would replace this o'ring
how to test the oil filler with the smoke machine?
I received the baby oil, the smoke machine is ready.
we'll see tomorrow, to locate any leaks
I did my search for leaks.
plugged into the TB, I slipped the pipe under the butterfly so that the smoke goes all the way through the intake
another leak at the brake vacuum hose
leak video
ideally I think I would have to change the part, but for the moment I have sealed as much as I could
admission test at the intake manifold
admission test 1
oil filler tube test
ouil filler tube test
First of all, I don't have any leaks. (i think)
now i must do a run for test and take the values.
for the moment I do not go up the kn, I stay with the Mahle paper filter
I'm not going to say it's good yet but it's on the good way
before i reset DME by disconnecting the battery, doing an adaptation of TB and a 75km drive.
no fault and
The car works very well, even much better than before, between the leak and the IPD + TB82mm plenum.
I have a lot more torque from 3000rpm.
And funny thing, I have more attack when braking and I have the impression that the clutch is also going better.
today, 200 km, in all situations, national, city, traffic jam, motorway..
no fault
values check is topl and most importantly, it works!!!
I recovered a lot of torque from 2055/3000rpm
I validate
