The turbo seems to be leak free for now Oil return flows free and there is no excessive crankcase pressure. It seems that the oil change cured my leaking issues.
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Mot fail due to emissions, possible causes?
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What kind of cat do you have, originals or aftermarket? How are the exhaust manifold flanges, any signs of leaks? Everything tightened up as they should be? Even a small leak on the exhaust side before the lambda probe can cause problems with emissions. Twin tip exhaust pipes can cause problems unless you block the pipe without the MOT probe.
No fault codes of any sensors? Air temp, water temp, knock sensors, engine feel healthy when driving? Do you have a wideband lamdba gauge?
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Aftermarket catco cat is what I currently have.
There should not be any leaks before the
lambda. All new turbo seals were fitted when it was out along with copper locking nuts.
Only fault code I had was about the intermittent idle speed adaptation. I will recheck the codes.
The engine feels good to me but I have no comparison to any other S2.
No wideband lambda yet.
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Antsa,
Although I don't have this engine, I thought that a) you may have too much fuel at idle; b) the ISV is trying to correct, but is (intermittently?) maxed out; and c) these three things (common between a 7A and your motor) done in the order below, might be easy enough to check first:
- Try a code clear and pull again to confirm presence now. Is the code you got before this one?:
2231 (Blink Fault Code), 00533 VAG1551/2 Fault Code Number
Idle Speed Control Valve (N71)
Idle speed adaptation maximum limit exceeded or Minimum adaptation limit not reached
Sticky or binding ISV, Mass Air Flow Meter (G70) offset, additional air introduced between G70 and N71
Symptom: Idle speed too low, or too high, Add air leak.
How is the idle speed, fast, slow, smooth?
- Do a check of engine vacuum as delivered to the FPR at warm idle (see info at Dave's links going back);
https://www.s2forum.com/forum/techni...58#post1234758
- Could the ISV, MAF and connectors use a clean? Are your injectors all closing properly and not leaking while under pressure?
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Originally posted by Lago Blue View PostAntsa,
Although I don't have this engine, I thought that a) you may have too much fuel at idle; b) the ISV is trying to correct, but is (intermittently?) maxed out; and c) these three things (common between a 7A and your motor) done in the order below, might be easy enough to check first:
- Try a code clear and pull again to confirm presence now. Is the code you got before this one?:
2231 (Blink Fault Code), 00533 VAG1551/2 Fault Code Number
Idle Speed Control Valve (N71)
Idle speed adaptation maximum limit exceeded or Minimum adaptation limit not reached
Sticky or binding ISV, Mass Air Flow Meter (G70) offset, additional air introduced between G70 and N71
Symptom: Idle speed too low, or too high, Add air leak.
How is the idle speed, fast, slow, smooth?
- Do a check of engine vacuum as delivered to the FPR at warm idle (see info at Dave's links going back);
https://www.s2forum.com/forum/techni...58#post1234758
- Could the ISV, MAF and connectors use a clean? Are your injectors all closing properly and not leaking while under pressure?
To me the idle seems smooth, around 750 rpm when warm.
The vacuum to the FPR has to be tested.
MAF and its connectors were cleaned last summer.
About the injectors, I can't say for sure. If replacing the catalyst does not solve the problem my next step is to take the injectors out for a checkup.
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