A little while ago my CEL came on
Also I could not get over 0.4 bar no matter what

I took the car to the garage they plugged it in and said they couldn't read the ECU - they said the car must have been flashed

They tried again and this time they could read it
So they're guessing it isn't flashed
When I bought the car I was told it was stock

They said the CEL was showing the O2 sensors being the problem
but they said it might also be a problem with the MAF

So, they reset the CEL and did a quick run through the rev range
The car drove fine but still wouldn't boost above 0.4 bar

They said the CEL will probably come on again - if it does they'll swap the O2 sensors and MAF

They said that I probably had a boost leak too - causing a loss of boost

I agreed to drive the car until the CEL came on again and would take it back to them to check out, along with the probable boost leak

Anyway - I was driving today and the boost guage was going upto 1.4 bar?!
The CEL flashed a few times then went out

I did the same thing again and the same happened again
I tried again but this time the CEL stayed off

The car still shows boost upto 1.4 bar

does anyone have any ideas whats going on here?
why could i only get 0.4 bar last week and today it showed 1.4?
is the CEL the sensors? or could it be the boost issue?

Car is stock except for forge DV's

 

DISCONNECT THE BATTERY for a few minutes....
it'ts not the 02 sensors... but more likely the maf.... OR a boost leak...
diconnect the maf by unplugging it... u simply press the tab on the right side and pull it up... the cel will come on and stay on thats OK... if the car can boost past .4 bars then its more likely the maf... just dont get crazy on the gas...
there are a few other things you can do like pressure testing.... but before that you should pull on the black hoses coming form the Y pipe to the ICs and the ones under the car form the ICs to the turbos... see if one of them gave out....

 

When I had issues with MAF last time, my ABS and PSM CEL came on. I agree with Mark to unplug the battery for few minutes. I will listen to Mark, he knows a lot.

 

How do I stop the alarm from going off when i disconnect the battery?

 

Put Key in the ignition and turn it to on position (all lights displayed) then disconnect battery. Guys in the US don't have battery backup for alarm... we do!

 

I get a flashing CEL and misfire codes on cylinders 4,5, & 6 cruising on the highway in 5th gear around 3000 rpm. But I don't have a boost problem. Could my issue be related?

 

Is your car flashed? When was the last time you changed spark plugs? What kind are they?

 

The erratic behavior suggests diverter valves to me. If they stick closed you'll have trouble making boost, and if they stick open you could overboost.

 

The ECU is stock and the spark plugs are new (OEM Bosch). The coils and O2 sensors have been swapped and leak tests done but no shop can get to the bottom of it yet. I haven't changed the MAF but nothing indicates that's the problem. Any ideas?

 

THREAD HIJACK!!

 

Thanks Markski
The black hoses seem fine - is there any chance the end that connects to the intercooler came off?

I'll check the MAF when I get back tonight

The DV's are Forge and about 2/3 months old
Is it likely that they're at fault or not?

Someone else told me it could be the wastegates?
Does that makes sense?

 

Put your damn hands up...I'm armed

 

 

Good News...

I was putting my car through a few runs and it was running like a bag of ****
It was stuttering really badly - still making upto 1.4 bar through?!

Next minute my PSM and ABS lights come one!
Hurrah - I'm guessing my problem is the MAF?

So, do i need to chewck anything else yet? Or should I replace the MAF and see if thats helps first?

On a side note, the car seems the run better now the PSM and ABS lights came on
Is that possible? Are the lights coming on the same as disconnecting the MAF? Or is that just in my head?

 

I would disconnect the MAF and see what it does. If it runs well without the MAF, then you have to replace the MAF