NefMoto

Hey Guys,

I have a 1998 Euro Spec Manual B5 S4 tuned by MRC to 477hp and 638nm

I have a 551C box

Car was tuned recently and everything is/was perfect but again another EGT took a crap!

Both EGT's were recplaced in september 2010 together with a new MAF and new Lambda's but I have only driven 5000km since!

We took off the passenger side dodnwpipe and EGT this week to fix an oil leak and offcourse had to take out the EGT!

everything was back , oil leak fixed but the car trew a code yesterday evening after hesitating a couple times under full load!


17867 - Exhaust Gas Temp Sensor 2 (G236): Implausible Signal
P1459 - 35-10 - - - Intermittent

I am not in the mood of recplacing yet ANOTHER EGT sensor cause they cost 200

What is the best way to disable these in the ECU ?

http://s4wiki.com/wiki/Tuning#EGT

Is this the same for the Euro C box ?

I have posted a xdf for the C-Box with the needed variables included in the definition section. Are you sure you can just throw them out (your tune doesn't need them)? Do you have an EGT gauge? 

Can't seem to find the link?

I have a MRC tune with 1.45 peak pressure dropping off to 1.25

http://www.nefariousmotorsports.com/forum/index.php/topic,339.0title,.html

Have you already logged your EGTs with a EGT gauge or something?
If I remember right you don't have the EGT messure block with the C-Box.
I don't know how MRC calibrates their stuff, but in general if you code out the EGT sensors you have to make sure that you don't run too high EGTs otherwise you will .... up your engine pretty quick.

To your question on audizine regarding testing the sensors with a multimeter:
It's not possible to do that. The sensor is a Typ N thermocouple. It is usually not the thermocouple that fails but the sensor electronics. The signal for the ECU is a 100Hz PWM that is varried between 945-1050

My car isn't running high EGT's , I just had 4 EGT's take a crap in 2.5 years and not ready to buy a new one AGAIN, that would be 1000

The failures of the sensors have nothing to do with EGTs, but how do you know what EGTs you are running?

I don't indeed but I was told my MAP was made with EGT's in mind to not succeed the limit.

I am planning on putting in an aftermarket EGT sensor with a display in car to see what's going on but you get my point in getting frustrated these shitty 200e sensors taking a crap every time ...

What is your vision on disabling them or what do you think is the best thing I do in this situation?

I can understand your frustration with this. I have coded out the sensors for the same reason as well. But I run on E85 all the time which is less critical with the lower EGTs.

My point on this is, that anyone has to be clear that he throws out a major safety feature for his engine if the sensors are coded out. I wouldn't do that if I would not have an other way to have an eye on EGTs (for example aftermarket gauge). There are many scenarios which can lead to too high EGts even if the initial tuning was spot on, especially on binary lambda sensor cars.

I use the stock sensor thermocouples hooked up to an amplifier that puts out a 0-10V signal I can display and log with my Labview based logging system.

Indeed!

I do plan on running an aftermarket gauge then to keep an eye on things!

Don't my Lambda's and knock sensor cause the engine to cut power or shut off when something is wrong?

How does it work then with all the VAST and EPL cars, none of them have aftermarket gauges and I haven't heard of any failures yet?

I do want to be safe and not kill my engine, that's one of the most important things offcourse! I have never had my car shut off due to too high EGT's , the things just take a crap every once and awhile and that sucks BIG time  ::)

What about this idea I have , tell me if it's stupid! And maybe something better with the above in mind...

Here we go :

We have 2 EGT sensors in the car ! If both of them take a crap it's 400€ and you go insane !

I asked for pro's and contra's on coding them out BUT yesterday I was in my buddies S2 , we did some extreme pulls over 280km/h and his EGT's rised to 1020° ! Opened the hood and everything was glowing orange , very nice to see but this made me think about the importance of an EGT meter cause his KMS standalone does what the ME7 does in our cars and add fuel quickly to cool things down, if that feature wasn't on there he would have melted everything last night

So now that I understand that I was thinking what if we keep 1 OEM EGT, the passenger side (for you guys driver side) cause that’s the easy one to replace and keep all the features like dumping fuel to keep it all cool and being a safeguard for the engine , decoding the other one and put a 100€ EGT gauge in there just to monitor in the car?

ORRR am I thinking wrong and will the S4 normally not produce +950° on highway pulls and can I have em both coded out and put 1 gauge in there with a limiter that let’s me know when things get hot?

Cause the OEM dumps fuel in there to cool things down or limp the car when it goes + 940 ? Whereas having em decoded nothing will dump fuel in there and you just have to come off the gas to cool down the exhaust temps!

Last but not least, will loosing my 400cell Catalysts and add W/M help turn down the EGT’s a lot ?
Yeah I know lot of questions but I’m trying to get a lot of knowledge about these cars and how everything works

Thats really interesting... I am only getting one EGT code, so if i just decoded that one side, would i still have the protection from the other side (drivers side US).

Sometimes, this fault (implausible signal) is appear due to faulty lambda probe. I remember official paper from VAG about this.

But yes, in my experience, new EGT sensors is ruined after about 2-4 month after installation (about 5 cars with such situation). Very bad quality!

You can try to open and re-solder your EGT sensors, in some case, this will help.

Really interesting thought, so the GM flex fuel sensors work by outputting a 50-150hz signal depending on the ethanol content (50hz=0%, 150hz=100%).  Currently, there is only the Zeitronix ethanol content analyzer, which is $200 and requires a seperate GM flex fuel sensor.  Do you think there might be a way to hook up the GM flex fuel sensor to the EGT input on the ECU, possibly change the scale of what the Hz mean in the map on the ECU, and be able to log the ethanol content via ECUx rather than having to buy that separate Zeitronix gauge?  Electrical engineer's thoughts?

I have no idea if that would work, but if so I would think the pro wouldn't be EcuX logging. If that could work then I don't see why you wouldn't be able to base fueling on ethanol content.

For sure...if you can figure out how to get those map to correctly affect the fueling, etc.

I was thinking about it though, and for my purposes (checking ethanol content every gas tank), I wouldn't want to have to log with a computer anyways.  So I think I'm going a different route with that sensor just to check the content.  Would be sick to figure out how to make it true flex fuel though!

Last week checked codes , still the Knock and Bank 2 EGT, cleared codes and went on...
Yesterday friend of mine who's an electrician checked every connector that was visable , also checked with multi meter for signal on all wires , everything was ok !

Went for a drive , everything was fine for a few pulls it felt like a monster again and drove perfect!

Then BRRRR it bucked badly and also puffed alot of black smoke like a diesel (prob cause it was dumping fuel in there) and even with the N75 diconnected it struggled and hesitated!

Read codes again and this came up:

16712 (G61) Knock Sensor 1
P0328 35-10 Signal too high --Intermittent

17870 EGT Regulation Bank 2 Implausible signal
P1462 35-10 Intermittent

And a new one:

16486 Mass Air Flow Sensor signal too low
P0102 -- Intermittent

Cleared all these codes , went for a drive and again it drove PERFECT for 10 minutes , also pulled like crazy and then again BRRR it held in, pulled perfect, held in, hesitated etc etc , came home , but no codes stored yet!


Do you think my MAF is dead ?

Is the dead EGT causing all of this? I wanna code em out and install an aftermarket gauge but the OEM thread in the hole is M12 x 1.0 and all aftermarket sensors are 1/8NPT