Leon boost problems - OBD read out inside

[dj0nes]

Hey all,

I am new to the forum, I just picked up a Leon Cupra today, however it has quite a serious boost problem, when I try to accelerate 9 out of 10 times it will hold back and sometimes even backfire, the dump valve makes the right noise and when that rare time it does let me accelerate the turbo kicks in nice and hard.
I also seem to get a strong un burnt petrol smell from the car, I took the MAF off for part of the journey home which seemed to help a bit now when I put it back it's searching in idle and feels like it's going to stall.

Here are my readouts, I can see it's picked up a few misfires - unfortunately my scanner won't let me reset the codes so I cannot see which is relevant, anyone kindly suggest my first move?

-------------------------------------------------------------------------------
Address 01: Engine Labels: 06A-906-032-AJQ.LBL
Controller: 06A 906 032 DE
Component: 1.8L R4/5VT 0001
Coding: 11510
Shop #: WSC 79665
VCID: 64BB2F93E755
13 Faults Found:
17763 - Cylinder 1 Ignition Circuit: Open Circuit
P1355 - 35-10 - - - Intermittent
17766 - Shareware Version. To Decode all DTCs
P1358 - 35-10 - Please Register/Activate - Intermittent
17705 - Shareware Version. To Decode all DTCs
P1297 - 35-10 - Please Register/Activate - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16688 - Shareware Version. To Decode all DTCs
P0304 - 35-10 - Please Register/Activate - Intermittent
16687 - Shareware Version. To Decode all DTCs
P0303 - 35-10 - Please Register/Activate - Intermittent
16685 - Cylinder 1: Misfire Detected
P0301 - 35-10 - - - Intermittent
17545 - Shareware Version. To Decode all DTCs
P1137 - 35-00 - Please Register/Activate
16804 - Shareware Version. To Decode all DTCs
P0420 - 35-10 - Please Register/Activate - Intermittent
17947 - Clutch Pedal Switch (F36): Implausible Signal
P1539 - 35-00 - -
16686 - Shareware Version. To Decode all DTCs
P0302 - 35-10 - Please Register/Activate - Intermittent
17511 - Shareware Version. To Decode all DTCs
P1103 - 35-10 - Please Register/Activate - Intermittent
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-10 - - - Intermittent
Readiness: 0000 0000

-------------------------------------------------------------------------------

 

[dj0nes]

Little update - I have now managed to clear all the codes this morning, I took the car for a drive and for the first five minutes it was boosting great everytime with no second thoughts a bit further into the journey it went back to hesitating, not as bad as it did yesterday but still 6/10 times refusing to fully boost, had it plugged in at the time but no faults have been recorded despite the ongoing problems.

 

[mk1cupradave]

I had the same problem last week. It could be a number of things. Firstly i would have a look for any boost leaks. Have a look at the pipes where the pcv valve is located and the front of the engine. Also check the pipe coming from the right hand side of the rocker cover as this is also common. Failing this would look at the maf sensor (can be logged on vac com). The n75 valve is also another common part that fails.

 

[mk1cupradave]

http://www.seatcupra.net/forums/showthread.php?t=356623

Looking at the faults and having the maf fault i would try and get it on vac com as this is the most likely cause.

 

[dj0nes]

Hi Dave, thanks very much for your reply forgive my ignorance as I am really not sure but is VCDS not the same as Vag com just a lite version?

But I shall certainly have a look over the engine today, it's my first turbo so it's new to me but it's all fun and games lol.

 

[mk1cupradave]

I believe they are the same thing as VCDS stands for VAG-COM Diagnostic System.

I had mine smoke tested as i couldn't see any splits in the pipes without removing them. It was £30 so i thought it was worth it rather then messing about removing pipes.

My Leon was my first turbo car also. They are easy to get your head around once you have a play.

 

[dj0nes]

Cheers for your help mate, I shall be sure to report back with my findings.
Did you get a smell of unburnt petrol too by the way?

 

[dj0nes]

Little update - took it for a hour drive and hooked it back up to my laptop with the following results.

Address 01: Engine Labels: 06A-906-032-AJQ.LBL
Controller: 06A 906 032 DE
Component: 1.8L R4/5VT 0001
Coding: 11510
Shop #: WSC 79665
VCID: 64BB2F93E755
1 Fault Found:
16804 - Catalyst System; Bank 1: Efficiency Below Threshold
P0420 - 35-00 - -
Readiness: 0000 1001

I am thinking maybe this is all linked to the Piperx induction kit which is on there which may have sent the MAF bad? No CEL at the moment.

 

[mk1cupradave]

what exhuast are you running. This code doesn't is normally due to fitting a dp and decat. I would start by checking the exhaust for leaks. Have a look round the post 02 sensor where the clamp is that connects the down pipe to the rest of the exhaust. If not there is a chance that your cat is full of rubbish.

 

[mk1cupradave]

16804/P0420/001056 - Catalyst System; Bank 1: Efficiency Below Threshold

Possible Causes
Leakage in Intake and/or Exhaust System
Catalyst faulty
Oxygen Sensor(s) faulty
Oxygen Sensor(s) Control faulty

Possible Solutions
Check Intake and Exhaust System for Leaks
Check Catalyst
Check Oxygen Sensor(s)
Check Oxygen Sensor(s) Control
Perform Oxygen Sensor(s) Aging Check

 

[dj0nes]

I am not sure mate, I don't know the history of the car but it's definately not standard. Looks like full stainless steel.

I am going to start with the spark plugs I think and basically just do a standard full service to see if that helps if not as seeing as I am not sure of the history it would make sence. If that doesn't solve it I will go down the leak test route I think

 

[mk1cupradave]

if it is an aftermarket exhaust and has a decat you will need one of these as the 02 sensor can show a fault.

http://www.ebay.co.uk/itm/Lambda-Sp...CarParts_SM&hash=item4ab91bc2d3#ht_694wt_1037

you will need to check the fitting not sure if this will fit, only used as an example.