Rough engine after egr change 1.4 fsi BBY

A

ATO

Member
After changing the egr valve my engine is running rough and the abs and etc light comes on randomly. Before changing the EGR valve it was only the etc light coming on and only if I revved the engine.

I've been working on this issue for a while.
The fault code is p0106 or p155300 on vw witch indicate a bad map sensor.

The long term is on negative indicating a ritch fuel mix.

Things I've done so far:
Clean out the throttle body
Change fuel filter
Change air filter
Change map sensor
Change rear lambda sensor

After changing the air filter i got a big improvement, and maybe I felt some improvement after changing the fuel filter but I'm not really sure.

My ideas going forward is:
Electrical issue in the cable to the egr- how do I check that?
Faulty injectors

Please help a2oc kenobi, you're my only hope
 
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Have you considered the front lambda? That has a much greater influence on fuelling than the rear one (if my understanding is correct) - a genuine NGK/NTK LZA11-V1 (aka. 1825) may well help if the existing one is aged or an aftermarket - on our AUA fitting a new NGK eliminated the recurring MAP sensor errors that had plagued us for a year or so.
 
Robin_Cox said:
Have you considered the front lambda? That has a much greater influence on fuelling than the rear one (if my understanding is correct) - a genuine NGK/NTK LZA11-V1 (aka. 1825) may well help if the existing one is aged or an aftermarket - on our AUA fitting a new NGK eliminated the recurring MAP sensor errors that had plagued us for a year or so.
Click to expand...
May the force be you with, Robin.
Screenshot_20230127-223742.png

Mac.
 
Robin_Cox said:
Have you considered the front lambda? That has a much greater influence on fuelling than the rear one (if my understanding is correct) - a genuine NGK/NTK LZA11-V1 (aka. 1825) may well help if the existing one is aged or an aftermarket - on our AUA fitting a new NGK eliminated the recurring MAP sensor errors that had plagued us for a year or so.
Click to expand...
Thank you, that's a good idea!

I'm thinking that since the fuel mix is ritch it would be unlikely that the injectors is the problem. If the injectors was the problem then it would be that they are dirty and gives out too little fuel making the fuel mix lean.

The throttle body looks so fresh otherwise that would be a good start as well.

I found a row in one of the vw scanner settings called "asjustment of egr" and after that it ran smooth for 30 minutes. Is that a setting that anyone that changes the egr is supposed to run?
Anyway the problem occurs seemingly randomly so I might be fooled by a good 30 minute run that just happemed by chance :(
 
Robin_Cox said:
Have you considered the front lambda? That has a much greater influence on fuelling than the rear one (if my understanding is correct) - a genuine NGK/NTK LZA11-V1 (aka. 1825) may well help if the existing one is aged or an aftermarket - on our AUA fitting a new NGK eliminated the recurring MAP sensor errors that had plagued us for a year or so.
Click to expand...
Having just suffered an emissions related MOT fail and read up on Lambdas a lot, I think you are right that the pre cat lambda (036906265J AUA/BBY) does the heavy lifting on fuel mixture
 
birtyA2 said:
Having just suffered an emissions related MOT fail and read up on Lambdas a lot, I think you are right that the pre cat lambda (036906265J AUA/BBY) does the heavy lifting on fuel mixture
Click to expand...
Turned put the front lambda was one of the first things I changed. I looked through my reciepts just now, so it's not that.

Probably the throttle body then..
 
16490/P0106/000262 - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal
Possible Symptoms

Erratic Idle

Possible Causes

Wiring and/or Connections from/to Manifold/Barometric Pressure Sensor (G71)/(F96) faulty
Leak in Air Intake and/or Exhaust
Manifold/Barometric Pressure Sensor (G71)/(F96) faulty
Engine Control Module faulty

Possible Solutions

Check Wiring and/or Connections from/to Manifold/Barometric Pressure Sensor (G71)/(F96)
Check for Leak in Air Intake and/or Exhaust
Check/Replace Manifold/Barometric Pressure Sensor (G71)/(F96)
Check/Replace Engine Controle Module

Looks like you have checked/changed everything. Might be worth checking the wiring between the sensor and ECU. Not speaking from experience myself but I note that lower quality parts can cause problems judging by other forum posts.

The fault code suggests implausible output from the sensor, have you looked at the measuring blocks in vcds, this might give you a sense of what output is being received but I have no idea what values you might expect for a plausible signal.
 
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birtyA2 said:
16490/P0106/000262 - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal
Possible Symptoms

Erratic Idle

Possible Causes

Wiring and/or Connections from/to Manifold/Barometric Pressure Sensor (G71)/(F96) faulty
Leak in Air Intake and/or Exhaust
Manifold/Barometric Pressure Sensor (G71)/(F96) faulty
Engine Control Module faulty

Possible Solutions

Check Wiring and/or Connections from/to Manifold/Barometric Pressure Sensor (G71)/(F96)
Check for Leak in Air Intake and/or Exhaust
Check/Replace Manifold/Barometric Pressure Sensor (G71)/(F96)
Check/Replace Engine Controle Module

Looks like you have checked/changed everything. Might be worth checking the wiring between the sensor and ECU. Not speaking from experience myself but I note that lower quality parts can cause problems judging by other forum posts.

The fault code suggests implausible output from the sensor, have you looked at the measuring blocks in vcds, this might give you a sense of what output is being received but I have no idea what values you might expect for a plausible signal.
Click to expand...
Yes, I think I will check the wiring before I replace the throttle body.
The biggest reason I don't want to replace the throttle body is that it seems so fresh, somone probably changed it before I bought it.

If there would be an air leak on the vacuum system, then the fuel mix would show up as lean if I'm not mistaken, so it's probably not that. It could be something that blocks the airflow though.
 
ATO said:
Turned put the front lambda was one of the first things I changed. I looked through my reciepts just now, so it's not that.

Probably the throttle body then..
Click to expand...
was it an NGK/NTK that was fitted or generic aftermarket? We had a generic fitted 3 years ago that gave sporadic and finally regular rich mixture errors exemplified by MAP sensor fault codes exactly as you list above. Replacing this with an NGK in November without making any other changes has eliminated all of the reported MAP / air leak errors. Plenty of comments on here about performance of original vs non-original lambdas which was what eventually persuaded me to bite the bullet. Ours also came without a connector that meant the original plug was swapped over - towards the end there were errors also relating to the lambda heater circuit being faulty suggesting there was a wiring issue as well.

Do you ever have reported misfires? (thinking about the uneven idle and other symptoms we had to begin with) - our idle was attributable both to a filthy throttle body (replaced), dud EGR, a mixture of spark plugs, old leads and subsequently the AUA coil unit being bad - I know the BBY has individual coils per cylinder so less likely to be fixed by one piece being swapped. Our new TB was adapted using the VAG401 and managed to pass the adaptation criteria at the time.
 
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