Hi,

Thought I'd share this with you guys. I was getting poor mpg on a regular basis and also thought performance had gone slightly down. At first I figured I was just booting the car more heavily than before and was getting used to the performance. Then I started testing, tried driving with a feather light foot, changed air filter and checked tyre pressures.. the usual drill. No change what so ever, I was still gulping down over 10 mpg more than I used to.

Today I visited the local skoda garage and them check the car. Diagnostics showed nothing, so I asked the mechanic to reset the ecu self learning data or whatever.. At this point he started up the car and was checking all the adjustments and noticed the car wasn't breathing too good. I was getting close to 40% too little air in @2500rpm and it kept getting worse at higher rpm. Diagnose - MAF knackered.

The car is just over a year old and has 35k miles on the clock. Naturally it's a warranty job - no probs there. The car is getting serviced next thursday and hopefully all the worries will be over.

Just glad it got sorted cuz I was getting a bit paranoid...

Anyways, in case you notice poor performance (even slight) and/or your fuel economy suddenly goes boinkers - have your MAF checked.

Ohh and the only mod is cupra 160 intake (yes, regular skoda air filter).

Hi,

At this point he started up the car and was checking all the adjustments and noticed the car wasn't breathing too good. I was getting close to 40% too little air in @2500rpm and it kept getting worse at higher rpm. Diagnose - MAF knackered.

Ohh and the only mod is cupra 160 intake (yes, regular skoda air filter).

So what you mean is the AFM/MAF was under-reading, 40% low.... Rather than the engine was actually getting too little air...

J.

I guess that would be technically correct, yes. I haven't got good enough clue on how these things work etc, but what you're sayin would make sense - now that I'm thinking about it.

Now as I understand it, MAF measurements are used to calculate the optimal fuel / air mixture. In my case it was underreading, so would that cause ECU to push more fuel through to achieve normal power and thus in effect over fueling the engine enough that I was puffing it out in black clouds or would it mean it wasn't supplying enough fuel so I would have been pushin the pedal further down to achieve normal performance? Both of these things naturally causing higher fuel consumption..

One more thing. I've read somewhere it should be safe to diagnose possible MAF failures by just disconnecting the MAF and having a spin. It's said this should convert the car to factory "default map". Would this be a good/harmless thing to try? Maybe Lummox or someone more educated than myself could drop a word on this..

It will to a default setting and if the MAF is knackered enough then yes it will seem better.

Forgive my ignorance, but, if the MAF is disconnected, and the car returns to the factory map, what happens to your re-map?

Forgive my ignorance, but, if the MAF is disconnected, and the car returns to the factory map, what happens to your re-map?

Anyone?

By referring to default map, it actually goes into some sort of "fail safe" mode. I tested disconnecting the MAF wires yesterday and can confirm the engine goes limp. It felt like driving a 1.0 litre 20 years old Fiesta. I had huge troubles reaching 120km/h on a motorway.. which would be around 2500 rpm on 6th. I crawled out of the motorway and reconnected the MAF wiring and hey presto - it was back to it's normal slightly crippled self. Plus the added benefit of having fault codes and engine management light switched on.. So, after this experience I recommend ppl won't try disconnecting the MAF wiring as it'll just make things worse.

Well, all in all I'm just happy it's getting sorted out by the dealer tomorrow. Will report back after getting me new MAF.

And as an answer to your guestion - nothing happens to your remap, it'll be fine right after you plug the MAF wiring back in.

Just got my car back from the dealer @lunch break. Haven't had the time to properly test it out yet, but the initial feeling is that things are better. One thing I noticed was noticeably shorter turbo whistle while accelerating and the general feeling of car being somewhat faster. From the turbo whistle & gutt feeling I jumped the conclusion that the turbo is spooling up faster than pre-repair. So I reckon things should be in a much better shape now.

I'll have a proper go at the car on the commute home from work (~45 motorway miles). Also will see about the fuel consumption then.

The dealer also said the car was showing somewhat better values now than what the factory default values are. I guess the pd160 intake comes into play there

Can't wait to get my pipercross filter soonish..