WEIRD - Abnormally quiet car after flash
 

So, I decided to install a catless EL header, catless resonated frontpipe and custom muffler. After I installed everything, I flashed one of Wayne's roms using tactrix. Car ran great up to that point and made great roaring sound.

Unfortunately, I got stopped by the police, and in my country it is illegal to modify the exhaust, so they forced me to have my car inspected within a week. So that day I put back the stock header and flashed the original rom. I noticed the car sounded quieter than before, but i thought it was only my imagination.

So I took the inspection, and right after that I put again the catless header, and started the car with the stock rom: car sounded really quiet, almost as if the header still had a cat. Also, like you all already know, the cold start can be very loud being catless, but it wasn't the case. The revs climbed high as usual during cold start, and my house should all be shaking, but it didn't happen. It sounded really, really quiet. Definetely not normal.

So, then I flashed again one of Wayne's roms, and still the same thing. The car still sounds as if it were catted. And my butt dyno tells me it isn't delivering all the power it should. Something isn't quite right and I don't know what it is. I took it to have it checked for exhaust leaks and they didn't find anything. I'm a total newbie but could it be something related to the cams or vvt? I haven't got any check engine lights as of yet. Any ideas would be welcome.

tunes car reduce startup noise, less rpm less ignition retard means less noise at startup.The noisy high rev start iscto heat cat in header, so useless with catless header

Yes, I know. I just find it weird that it used to be really, really loud the first time I flashed Wayne's rom, and then when I flashed it again, now it's really quiet and not just on startup, but during all driving. And I'm getting the impression I'm not getting all the power.

log vvt cam positions if they are not moving with rpm cams may not have activated

Sorry for taking long to answer, but I'm a total rookie and I've gone through all the hassle of learning how to use techstream and logging :bonk:

here it goes:

https://i.imgur.com/dZFXrgJ.jpg

that looks normal


but also log the realtime cam positions and make sure the intake and exhaist cams actually change values when you rwv engine

https://i.imgur.com/b0K5yaS.jpg

So I've logged VVT values with techstream and the image you see is after starting the car, during idle. After that I stepped on the throttle most of the values rised (vvt change angle, etc.).

I also tried slewing the cams from bank 1 and 2, and the car almost stalled, so that leaves me thinking that they are working properly and the problem lies somewhere else.

What do you think? Could it be simply a bad ECU?

cams likely fine


doubt it ecu if it goes bad nothing runs


flash back stock tune if its just basic mods on petrol see if its all normal then

I've just tried flashing the stock rom again. Car was cold so right after turning it on, revs climbed up to almost 2000. Car should be pretty loud and my whole house should be shaking, but didn't happen. It sounds almost like stock catted, seriously. It's really weird. It's almost as if the exhaust was clogged or something.

I've also tried one of OFTs roms for the first time, and the problem remains. Same goes with Wayne's rom.

And like I said, car is totally stock (including intake), except for the catless front pipe and catless header.

I've checked again thoroughly for exhaust leaks, and there aren't any.

Any ideas? I'm desperate and the dealer won't open until september. I don't know what else to do.

I'm using romraider's utility to compare images. I'm comparing the original image I downloaded and the very same image after flashing it into the ecu and driving 100km, and apparently there are 3 differences.

Tables "MAF sensor scaling", "Intake CAM advance angle normal AVCS" and "Intake CAM advance angle safe AVCS" are all zeroed out in my ECU. Is that normal?

https://i.imgur.com/WFTodrX.jpg
https://i.imgur.com/s3MkO0l.jpg
https://i.imgur.com/vASppRM.jpg

@Apsley Garrard they are the comparison. So shows the delta between the maps. At on the menu at the top left of the table you need to change the view option.

Check one of your cats has not disintegrated and blocked exhaust

I took the car to my local mechanic. He took out the whole exhaust line and checked it. There were no trace of anything blocking the exhaust.

I'm taking it to the dealer on the 1st of september since it is still under warranty. Do they have any way to know that I've been doing things to the ECU? It would suck to have the warranty removed...

Thank you very much for your help :thumbsup: