I'm getting rough and/or weak acceleration under hard acceleration. VAG says:
EGT 1 short to ground (intermittent)
EGT 2 implausible signal
intermittent multiple/random misfires cyls 1, 2, & 3
Went out and did some logging of blocks 015 (bank 1 misfires), 112 (EGT & enrichment), and 220 (EGT #1 regulation) under extreme acceleration (running WOT through 4th gear).
Got zero misfires (grrrrrr!) but saw some interesting things:
EGT 2 stuck at 945 degrees (the minimum) when EGT 1 gets to 1020-1030.
Enrichment of both EGT sensors seems to match - so EGT 2 is running enriched at the same time as #1, but temp never changes

I need to switch the power output stages to see if that's the misfire culprit, yet.

The Bentley CD describes using the VAG 1598/31 cable to check for short to ground in my wiring to determine if the short-to-grnd problem is in the sensor or the harness. Is there another way to do this with available tools? Is there a way to verify short-to-ground in the sensor?

Thanks in advance,

Bill

I had one go bad-- I think the "short to ground" means it's toast. Same symptoms, car would shutter @ WOT.

I had both replaced while I was at it.

Do a search-- you'll find plenty of company in the B5 S4 forum, at least.

...should probably do both, but $$$ is a little tight, right now.

Took my AR in last week for general check up after buying it from private seller. Car is mint but mechanic thought clutch was slipping until he noticed RPM did not spike and mentioned the EGT was the problem. I get the car back tomorrow (they are replacing every seal in the car - Every and doing the timing belt now, becuase I can get it all under CPO warranty.) Once I get the car back I will post what they found as the issue and what they did to fix.

I am having the same issue with my car. They want me to replace the EGT's but I am not sure if the sensors or the harnesses. You will have to let me know how its going and what teh ultimate fix was. I would really not have to buy new EGT's.

Hi!!!
How do you fix your problem issue about the ECU error with the EGT:impausible signal?????? Did you have to replace both sensors or what???
Or was about yhe O2 sensors???
Thanx, Carlos

I got the EGT sensor G235 error code. Can anyone share the detail as to how the Bentley CD describes using the VAG 1598/31 cable to check for short to ground in my wiring to determine if the short-to-grnd problem is in the sensor or the harness?