Hello, colleagues!

 

The car is an Octavia 1 Combi, 1.6 petrol with LPG, engine code BFQ, athmospheric motor without a turbo.

On a cold start, it runs quite rough for about 2 minutes and sometimes even tries to stall.

There's a constant "lean mixture" error with code P0171 when running on petrol, and at low RPMs/idling, the check engine light might come on, but even if it doesn’t, the error is logged.

VCDS diagnostics show that while driving at full throttle (100% throttle opening), 60 grams of air per second pass through the MAF sensor. Should it be more?

 

When starting at idle at operating temperature, the reading is 1.9-2.20 grams/sec. Should that be higher?

 

I tried running the engine without the air filter, and at idle, the reading is the same as with the filter in place.

If I disconnect the MAF sensor before a cold start, the car runs fine.

 

Please advise if I should replace the MAF sensor right away, or if there’s a chance something else might be causing the issue.

I attach log file.

 

Thank you!

 

 

 

 

 

 

 

 

xls LOG-01-002-003-062.xlsx

1 hour ago, KalinKB said:

VCDS diagnostics show that while driving at full throttle (100% throttle opening), 60 grams of air per second pass through the MAF sensor. Should it be more?

 

When starting at idle at operating temperature, the reading is 1.9-2.20 grams/sec. Should that be higher?

 

I tried running the engine without the air filter, and at idle, the reading is the same as with the filter in place.

If I disconnect the MAF sensor before a cold start, the car runs fine.

The standard air filter box (with a reasonably new filter) will flow air for at least 220bhp, say 3x what a 1.6non-turbo makes. Not all of this air passes through the MAF!!

 

Your better running with the MAF disconnected (and hence the default air map) indicates that you need a new genuine MAF.

Okay, I will test it again, cold start while it's running idling, I'll disconnect the MAF to be sure.

Is it mandatory for maf to be original, or can it be aftermarket from Hella?

4 minutes ago, KalinKB said:

Okay, I will test it again, cold start while it's running idling, I'll disconnect the MAF to be sure.

Is it mandatory for maf to be original, or can it be aftermarket from Hella?

MAF - Buy pattern, buy twice (or more).

22 minutes ago, Paws4Thot said:

The standard air filter box (with a reasonably new filter) will flow air for at least 220bhp, say 3x what a 1.6non-turbo makes. Not all of this air passes through the MAF!!

 

Your better running with the MAF disconnected (and hence the default air map) indicates that you need a new genuine MAF.

Okay, I will test it again, cold start and while it's running idling, I'll disconnect the MAF to be sure.

 

Is it mandatory for maf to be original, or can it be aftermarket from Hella?

2 hours ago, KalinKB said:

Okay, I will test it again, cold start and while it's running idling, I'll disconnect the MAF to be sure.

 

Is it mandatory for maf to be original, or can it be aftermarket from Hella?

 

2 hours ago, Paws4Thot said:

MAF - Buy pattern, buy twice (or more).

How much clearer do you want this!?