Recently I was racing in a city and suddenly the errors of Service Engine Soon, KEY and AFS OFF came! The car engaged some kind of "emergency" mode, barely responding to the throttle. I stopped, made attempt to start again - but it didn't turn on, even a starter did not begin to spin. Waited 5 minutes with the taken off terminal on the battery - and it started normally and driven ok. After a couple of days, this situation repeated - all the lights came on again!

And so the problem came - now car rides like it has 250hp, not 316, especially at low RPM (1000-3000).

I went to the dealer, there indeed was an error on headlights, on adaptive cruiz-control and that's all! No errors of the engine or gearbox. The oil in the gearbox and engine is new, throttle bodies were cleaned, sparks are ok and they performed the full adaptation of ECU - but the car still rides like it has less power. The only thing they found, that gasket between the catalyst and manifold is burned (and producing the loud sound) and they will replace it on the next week, but I don't beleive it could cause any power lost...

So, what to check?

1) I have Berk's HFC for one year and I have driven with them about 25000 miles. Maybe it's them dying?

2) Electricity. I can't explain why SES, KEY and AFS OFF came and I don't know if it could cause some power loss... But when it came into the "emergency" mode - maybe some kind of valve timing control sensors working incorreclty?

3) Maybe fuel pump malfunction...

4) Please, feel free to help me out what to check else!

 

the strange thing is that today car drives normally, and I feel almost no power lost, except the low rpm's 1000-2000...

Car's ecu adjusts someway or maybe it will happen again?

 

I have no idea what's inside the Berk HFC's, but I know from regular ceramic cats I've had on previous cars that the internal honeycomb can break apart and lodge further downstream inside the exhaust. If this happens it can cause strange intermittent power loss symptoms like you're describing as the broken piece moves around and lodges in different places. Usually, there is a lot of rattling from the exhaust before it ever gets that bad though, so it's not likely you wouldn't know something was up. Anyway, it's a long shot, but I thought I'd mention it just in case.

 

thank you for the info!

my exhaust is Berk's HFC -> Moroso Spiral Flow resonators -> Borla cat-back and it rattles crazy even when it was new!

btw, the gasket between the manifold and catalyst is burned and I can smell gasoline all the time, but I'm not sure it would cause any power lost...

 

damn, i just bought the berk hfc aND hopefully that doesnt happen to me..;-/

 

OK, now it seems like, when it's rather cold outside - car drives normally, no lags, no power lost...

But when it's hot, especially in the traffic jams - car starts to lag and throttle feels weak...

Any clues?

 

not quite sure what heat soak is but it sounds like that AFAIK...do you have AM intakes?

 

https://g35driver.com/forums/media-s...years-old.html

Check out that thread, maybe it is your berk hfc's, take them off and see if they are done. Considering 25,000 miles/year is almost equivalent to 2 years worth of driving for most people