Hi all,
I've been chasing my tail for a while with a very strange MAF discrepancy issue between bank1 and 2 on my car (Audi RS6 C5 2003), so I'm now looking for guidance from the bright minds.
Symptoms are that - as seen on the advanced measuring values on my Hexnet- as long as the engine temp (coolant) stays below 80°C, readings on both MAFs are perfectly aligned within a 5-7% margin, but above 80°C, value of maf bank 1 starts to decrease little by little compared to bank 2. When the engine reaches a stable temperature (90-95°C), the discrepancies between banks are as high as 70%, and like 40-50% when idle... Of course I get a fault code on the engine ECU (and that's the only one) saying I have implausible MAF discrepancy : '17416 - Mass Air Flow Sensor 1/2 : Implausible Signal - P1008 - 004 Intermittent'.
To cut a long story short, I've already checked all hoses (including vaccum hoses) and seals, swapped the MAFs (same readings), checked the SAI valves/system, changed the EVAP solenoid (N80), along with the N112 and N249, without success. A quick air pressure leak test on the air inlets didn't show anything to worry about...
Sooo after chasing a physical/mechanical problem (maybe it's still the case!), I start to wonder whether something could be wrong with the control /electrical system, like - off the top of my head - the engine ECU not receiving correctly the temperature sensor of one of the MAFs for gaz expansion compensation. Would that explain the strange and slow shift around 80°C? Could a faulty ECU remap create such a phenomenon (my car is remapped but rewriting the stock map didn't change anything, except performance) ? Still scratching my head on this issue, so any help/suggestion is welcome!
Best
I've been chasing my tail for a while with a very strange MAF discrepancy issue between bank1 and 2 on my car (Audi RS6 C5 2003), so I'm now looking for guidance from the bright minds.
Symptoms are that - as seen on the advanced measuring values on my Hexnet- as long as the engine temp (coolant) stays below 80°C, readings on both MAFs are perfectly aligned within a 5-7% margin, but above 80°C, value of maf bank 1 starts to decrease little by little compared to bank 2. When the engine reaches a stable temperature (90-95°C), the discrepancies between banks are as high as 70%, and like 40-50% when idle... Of course I get a fault code on the engine ECU (and that's the only one) saying I have implausible MAF discrepancy : '17416 - Mass Air Flow Sensor 1/2 : Implausible Signal - P1008 - 004 Intermittent'.
To cut a long story short, I've already checked all hoses (including vaccum hoses) and seals, swapped the MAFs (same readings), checked the SAI valves/system, changed the EVAP solenoid (N80), along with the N112 and N249, without success. A quick air pressure leak test on the air inlets didn't show anything to worry about...
Sooo after chasing a physical/mechanical problem (maybe it's still the case!), I start to wonder whether something could be wrong with the control /electrical system, like - off the top of my head - the engine ECU not receiving correctly the temperature sensor of one of the MAFs for gaz expansion compensation. Would that explain the strange and slow shift around 80°C? Could a faulty ECU remap create such a phenomenon (my car is remapped but rewriting the stock map didn't change anything, except performance) ? Still scratching my head on this issue, so any help/suggestion is welcome!
Best
Last edited: