Surging/Throttle Issues in chip mode. Have Vag codes. Need HELP!

[gordongekkos4]

My '01 6-spd S4 has been experiencing some throttle issues. It seem to be missing smoothness in throttle transitions (throttle cut/surging if you like). It seems to appear intermittently only when in chipped mode (APR 93 setting-1 bar boost). Especially when on the track. Usually after the car has been pushing hard for at least 10 minutes it starts. Most noticeable as I come out of WOT slightly...it will begin to feel like car is bucking/sputtering/surging. If I put the car back in stock ECU setting, the issue disappears. New TBB and 710n's installed within last yr.

I just ran vag-com today after a weekend track event, and here's what came up...mostly misfires in cylinders 1, 2, & 3, and Exhaust Gas Temp errors (bank 1 & 2). What do you guys think? Bad EGT sensor(s)?? What could be causing the misfires...it seems to be on cylinders 1 thru 3??
--------------------------------------------------------------------------
17862- EGT sensor 1 (G235): Short to Ground
P1454 - 35-00

16684- Random/Multiple Cylinder Misfire Detected
P0300 -35-00

16685- Cylinder 1: Misfire Detected
P0301 -35-00

16687- Cylinder 3: Misfire Detected
P0303 - 35-00

16686- Cylinder 2 Misfire Detected
P0302 - 35-00

17870- Exhaust GAS Temp Regulation for Bank 2. Implausible Signal
P1462 -35-10 - - - Intermittent

17864 - Exhaust Gas Temp Regulation for Bank 1. Limit Reached
P1456 -35-10 - - - Intermittent

Also saw a code under Address 03: ABS Brakes
18258- Powertrain Data Bus: Missing Message From ECU
P1850- 35-10 - - - Intermittent

And Address 08: Auto HVAC Labels:
Note: Excessive Comm Errors

[alosh]

i would like to know also...

i have apr tune and it really feels like a massive loss of power/torque.

is this what you have?

[gordongekkos4]

While it's surging, there may be a loss of power, but in general, no.

[Blue AWD]

umm EGT sensors are bad.

[S4 in_lowplaces]

check The tech section for my reply.

[ThirdStrike]

umm EGT sensors are bad.

+1
also you could have a failing abs control module.
www.modulemasters.com

[gordongekkos4]

Any idea why the throttle issues are only noticeable while in chipped mode?

[S4 in_lowplaces]

DId you buy the chip used or did APR instal it? If you bough it off somone you might have not done the throttle adaptaion. Also when i bough mine the first 300 miles or so it was also getting thottle cut, from what i hear the ECU need som time to adapt to your driving habits.

The thing is, we know for a fact that your EGT sensor is bad. A bad EGT sensor will cause shitty performance. Get it fixed. Clear your codes and run vag again. Honestlythats where i would start. You coudl also do a boost leak test. Start there and move forward.

[mholme]

Any idea why the throttle issues are only noticeable while in chipped mode?

You're running higher boost...It exposes weaknesses in other components,ignition, pressure, etc. When I chipped my car it blew the tbb right under the hose clamp afte a few miles. Even when I put the samco boot on, it still flew off until I clamped the bolts down uber tight..

[mholme]

DId you buy the chip used or did APR instal it? If you bough it off somone you might have not done the throttle adaptaion. Also when i bough mine the first 300 miles or so it was also getting thottle cut, from what i hear the ECU need som time to adapt to your driving habits.

It shouldn't have to adapt at all. You just need to do the adaptation once installed.

[gordongekkos4]

I bought it used from someone on the forums. It worked fine for a while, I didn't notice any issues until the vehicle was on the track. I suspect that's when the EGT sensor(s) started dying. And maybe the EGT sensor worsens after the car gets hot...which if true, could explain why this happens only intermittently and usually after first 10 minutes or more of hard tracking. I've never heard of having to do any kind of throttle adaptation w/ chipped ECU's. Unless it was something I did when I put it in originally...can't remember if that was on the instructions or not. What exactly is that, is it necessary, and what do you have to do? Also, I can't remember if the sparkplugs were gapped properly when installed. What ramifications could that cause?

[mholme]

Throttle body adaptation: Once you've reconnected the ECU, turn the key to the second position, don't start the car. You can hear a faint electrical, high pitch noise under the hood for about 25 seconds. When it stops, you're done.

[mholme]

I bought it used from someone on the forums. It worked fine for a while, I didn't notice any issues until the vehicle was on the track. I suspect that's when the EGT sensor(s) started dying. And maybe the EGT sensor worsens after the car gets hot...which if true, could explain why this happens only intermittently and usually after first 10 minutes or more of hard tracking. I've never heard of having to do any kind of throttle adaptation w/ chipped ECU's. Unless it was something I did when I put it in originally...can't remember if that was on the instructions or not. What exactly is that, is it necessary, and what do you have to do? Also, I can't remember if the sparkplugs were gapped properly when installed. What ramifications could that cause?

A bad EGT will make your car run like poo poo. It will cause misfires, rich running and limp mode. It worth the 280 or so bucks to have the car running right.

[gordongekkos4]

A bad EGT will make your car run like poo poo. It will cause misfires, rich running and limp mode. It worth the 280 or so bucks to have the car running right.

Agreed. I'll definitely be replacing the bank 1 EGT, if not both. That sounds like the culprit causing the agro. I think I'll do the bank one, test it out, then vag-com again to see if there's any more codes. If so, maybe do the bank 2 EGT at that point. Are those last two codes re. the ABS and Auto HVAC anything worth looking into?

[mholme]

I don't know about the other codes. Maybe just clear them and see if they come back? Is the ECU the right box for the car? was it recoded or anything?

[gordongekkos4]

Yeah, I'm quite sure this is the right ecu for the car. Someone else suggested that many of the codes "look like 1 or 2 O2 sensors are bad. the short ground code maybe indicates the )2 sensor is bad along the wiring, and not necessarily the sensor itself"

Another suggested to "watch blocks 015 and 016 and see how many misfires I get at idle, if it's counting fast the EGT failure might not be the cause of the misfires. You can swap the ignition amplifiers (top of the airbox) to see if the misfires move from 1-3 to 4-6"

Any of this make sense?

[Tifosi]

I agree with the others, with your symptoms, it is most likely that your passanger side EGT sensor is done.

[RudyH]

Any idea why the throttle issues are only noticeable while in chipped mode?

First fix the EGT sensor.

If the throttle issues still continues, log 001 (MAF) and 115 (Boost Specified vs Actual) and graph the 115.

[soccerplayer01]

ya mine does/did the same thing. my egt sensor is bad on my drivers side. what made mine worse was an intake and a race n75 valve. made the car lag sooo bad.