TÜV without catalytic converter, with diode

Hello everyone,

war grad beim HU & ASU. Hatte etwas bedenken wegen meinem Kat und den div. Gimmicks.

Just to remind you: My CAT (computer-aided technology) unit broke down, and I had to empty the case. I never installed the new (eBay) CAT unit.


My exam is over. The only modification was:

Chip's out - (Due to speed limit).

LDS - LMM Fault Simulator (Diode in the signal path of the Mass Air Flow sensor).
With that adjustment, the engine will then rev up smoothly, and there won't be any more black smoke.

Interesting to note: The turbidity value improved with each iteration.
'That's when you can see how the cat works when it gets hot.' ????????

A turbidity value of 0.34 with a maximum of 2.5 would be quite good considering the mileage.

Of course, the turbidity values kept getting better!!

The examiner was getting increasingly tired and was pressing the accelerator less forcefully (the tB value is increasing – this represents the acceleration time between the two engine speeds).

In addition, the protocol does not capture the "type" of acceleration. A nice inspector managed to get my old Golf 2 naturally aspirated diesel through the emissions test by first revving it up to 2000 RPM and then fully accelerating. The result was: 1st test (without trick) 2.5, afterwards (relevant for the sticker): 1.2 - 1.5

The diesel particulate filter (DPF) is a complete joke and only harms the engine!

Sure, here is the translation of the text from German to English:

"m" translates to "male" in English.

Hello!

I have an *** chip installed in my Audi A4 from 1996 (originally with 81 horsepower).
Do I need to remove it from the automatic unit (AU) because the speed will be too high?

Regards,
Carsten.

I don't know if the RPMs are too high. But if you've ever stood next to someone's car at the TÜV (German technical inspection), while they were flooring it and their engine was screaming at idle, then you know that every extra revolution can't be a good thing.

That's why the chip was outside.

For the sake of completeness: The 'CHIP' is an EEPROM memory chip inside the engine control unit (ECU), not a separate box or anything like that. A separate box does not increase the rev limit.

garth.brooks wrote:

Interestingly: The turbidity value improved with each run. "That's when you can see how the cat works when it gets warm." ????????

Hi garth.brooks,

This is once again a bunch of nonsense . The exhaust emissions are getting better because the deposits in the exhaust system are gradually being swept away over time. Of course, the way you accelerate (as Martin already mentioned) is also important.

Therefore, on the way to the inspection station (ASU), one should occasionally let a diesel engine "smoke" .