Holding back on full throttle

[James TQ]

As title says really, I'm just out for a dive, second and third gear on full throttle is Lumpy and feels like its holding back then letting go... It used to do it on the occasion Inthird part throttle, from previous scans I know a lambs sensor flagged up could it be this?

Im just sick of throwing money at the ****** thing, within the last few months iv cleaned the throttle body and the injectors

Any ideas?! Thanks.

 

[jojo]

Boost leak, MAF sensor?

 

[James TQ]

Forgot to mention its not all the time. Iv looked everywhere for leaks need a smoke test though is there a way to check a maf? How much are they new and can I upgrade it, will a s3 one fit?

 

[dre_S3]

had this problem for a while Ended up being the maf

 

[<tuffty/>]

Forgot to mention its not all the time. Iv looked everywhere for leaks need a smoke test though is there a way to check a maf? How much are they new and can I upgrade it, will a s3 one fit?

If its the MAF buy the right one for the car... the map is set for the type of MAF you have..

Fault codes and logging next...

What year/model is the car too?

<tuffty/>

 

[dre_S3]

Forgot to mention its not all the time. Iv looked everywhere for leaks need a smoke test though is there a way to check a maf? How much are they new and can I upgrade it, will a s3 one fit?

Go on euro car parts mate and use this code

Midmonth30 Gives you 30% off and when you take the old maf back you get £35 back so I got one today for £58 for a Bosch

 

[James TQ]

It's a 1999 a3 quattro

 

[Jay A3]

I had boost issues recently being intermittent. For me it turned out to be the maf.

 

[<tuffty/>]

I would be logging it first before chucking cash at it...

MAF issue present differently on different engine codes... AGU's rely heavily on the MAF and generally don't run very well at all when its on its way out... cars with ME7 ECU's like in this case the A3 TQS fair much better and can run happily with the MAF disconnected...

I would disconnect the MAF in the first instance and see if the car runs any better however... seeing as you have suggested there is a lambda fault then this should also be addressed (post up the actual code as this will help)

You do need to log the car though... airflow and boost on yours in particular... logging the lambda in your case won't be of much help as its a narrow band ecu...

The fact you know you have a fault somewhere and not addressed this won't be helping... only when you know all the known issues are resolved can you hope to find the ones you don't know about...

<tuffty/>

 

[James TQ]

right. codes are

16518
16500
16487
17524

one is a maf reading too high?

 

[karl210]

Go on euro car parts mate and use this code

Midmonth30 Gives you 30% off and when you take the old maf back you get £35 back so I got one today for £58 for a Bosch

did you get that offer in store or online mate? would it be available either way? cheers

 

[James TQ]

Karl, I called euro. You'd have to type In the code online then select collect in store hand your maf over there....

 

[<tuffty/>]

Research your fault codes here...
Category:Fault Codes - Ross-Tech Wiki

If using VCDS to scan then post up the output of the scan as it will have the fault code descriptions in them making it easy to work out whats going on else we will just need to look them up defeating the object a bit

16518
Not listed at Ross Tech which typically means its not a common issue but using the power of Google... (VW Online Technical Library - Diagnostic Trouble Codes (DTC) Tables)
"O2 Sensor Circ.,Bank1-Sensor1 No Activity Detected"

16500
16500/P0116/000278 - Ross-Tech Wiki
16500/P0116/000278 - Engine Coolant Temp. Sensor (G62): Implausible Signal

16487
16487/P0103/000259 - Ross-Tech Wiki
16487/P0103/000259 - Mass Air Flow (MAF) (G70): Signal too High

17524
17524/P1116/004374 - Ross-Tech Wiki
17524/P1116/004374 - Oxygen (Lambda) Sensor Heating Bank 1 Sensor 1: Open Circuit

Couple of possibilities here.. could be wiring... check earths under the battery tray as wiring faults on multiple sensors are normally all interlinked somehow...

If not that then it seems your Lambda is ******** so change it... its plausible the Signal too high fault is symptomatic of the lambda fault but get the Lambda changed first...

CTS looks like its dodgy too (common issue)... get a genuine one as ECP ones fail quite often...

See how that goes once fitted and codes cleared...

No point in diagnosing much else until you know the sensors are working as expected..

<tuffty/>

 

[James TQ]

Is the lambda located on the downpipe? Also what is a cts? Thanks for the info it's a great help.