Poor mpg help

[TommyCupra]

Hi

been having problems with mpg, getting low 20s at best and thats with driving like grandad.

Vagcom'd the car a few days ago and it came up with

16501 - Engine Coolant Temp. Sensor (G62): Signal too Low
P0117 - 35-10 - - - Intermittent

So i replaced it. The cars still fueling bad and it smells of petrol and idles bad, any ideas on what i should be looking at? The cars just had a new maf sensor, not sure what it was like before this as i've only had the car for 3 or 4 weeks.

Just about to vagcom again so will pop any errors up

 

[TommyCupra]

Address 01 -------------------------------------------------------
Controller: 6K0 906 032
Component: 1.8L R4/20VT SEA 0002
Coding: 11500
Shop #: WSC 00000
5 Faults Found:
16501 - Engine Coolant Temp. Sensor (G62): Signal too Low
P0117 - 35-10 - - - Intermittent
16795 - Secondary Air Injection System: Incorrect Flow Detected
P0411 - 35-00 - -
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
17524 - Oxygen (Lambda) Sensor Heating: B1 S1: Open Circuit
P1116 - 35-10 - - - Intermittent
16518 - Oxygen (Lambda) Sensor B1 S1: No Activity
P0134 - 35-10 - - - Intermittent
Readiness: 0000 1000

Am no pro at vagcom lol only the 2nd time i've used it.

 

[jNx]

One of your lambda sensors is either unplugged or is knackered looking at those last codes!

 

[TommyCupra]

Cheers will have a look tomorrow when its light

 

[Quikie]

does you car not run like a bag of balls? Oxygen (Lambda) Sensor B1 S1: No Activity

?????????

 

[TommyCupra]

it boosts fine and seems to be as quick as i'd expect. Just really bad MPG and jerky when at low revs

 

[pdcupra]

my car is shite on petrol too at the moment, and on a recent track day with a mate who has a cupra, i was averaging 9ish mpg and he was getting like 15-16 we were both nailing it too. Im going for new maf first

 

[stevegti6]

mafs fail all the time on these cars

 

[gavthelad]

id say lambda problem aswell....

 

[Havok316]

my car is shite on petrol too at the moment, and on a recent track day with a mate who has a cupra, i was averaging 9ish mpg and he was getting like 15-16 we were both nailing it too. Im going for new maf first

no tryingh to be funny here but maybe the computers sensors arent reading it correctly. Ive always been told the MPG computers arent accurate and only use them as a rough guide which im sure u know. Also noticed the instance u change to a different fuel it does read a crap MPG until you've topped a few times and the ECU has adjusted? The reason i said this as you mentioned u done it on a track day i assumed you changed from something like tesco 99 or V Power to Race Fuel 103 or similar?

 

[JKing]

Get the Lambda sensor checked then clear all the fault codes and do an ECU reset with a nice tank of 98 ron and see how it is then.

If you've got VAGCOM do a flow test on the MAF to see if it's reading low. Would put money on a new Lambda sorting it though.

 

[David_smith_909]

replace temp sensor and lambda, reset the ecu/clear codes and see what comes back

EDIT, just noticed you changed the temp sensor already, did you clear the codes after you changed it? might be a old code ......

 

[pdcupra]

no tryingh to be funny here but maybe the computers sensors arent reading it correctly. Ive always been told the MPG computers arent accurate and only use them as a rough guide which im sure u know. Also noticed the instance u change to a different fuel it does read a crap MPG until you've topped a few times and the ECU has adjusted? The reason i said this as you mentioned u done it on a track day i assumed you changed from something like tesco 99 or V Power to Race Fuel 103 or similar?

the car has been run on only v-power for the last 30,000 miles!!!! and i used v power on the track day too. I wasnt just going by the trip computer either - we both had a full tank, and after a few sessions i was just under half, and he was about 3/4 full. I notice it with day to day driving too, getting about 23mpg, and thats not foot down fun either!

 

[David_smith_909]

the car has been run on only v-power for the last 30,000 miles!!!! and i used v power on the track day too. I wasnt just going by the trip computer either - we both had a full tank, and after a few sessions i was just under half, and he was about 3/4 full. I notice it with day to day driving too, getting about 23mpg, and thats not foot down fun either!

u got any codes?

 

[TommyCupra]

no tryingh to be funny here but maybe the computers sensors arent reading it correctly. Ive always been told the MPG computers arent accurate and only use them as a rough guide which im sure u know. Also noticed the instance u change to a different fuel it does read a crap MPG until you've topped a few times and the ECU has adjusted? The reason i said this as you mentioned u done it on a track day i assumed you changed from something like tesco 99 or V Power to Race Fuel 103 or similar?

My onboard comp doesnt work so i use a spread sheet to work mine out

Anyways cars been in garage today and the faults looked at. Was coming up with CTS MAF and Lambda on there handheld kit so we reset all fault codes and its back again on Tuesday to be fixed. MAF and CTS sensors are brand new so if there buggered i should get money back or another

 

[freddie]

I had a problem like this b4 and it was only the fuel filter! Start your car up and leave parked up for a min or 2 then see if there is fuel on the road!

 

[TommyCupra]

Will have a look although it was serviced yesterday and fuel filter was changed

 

[Smoki333]

Defo Lambda knackered, if im right its the main one before the cat, so your probably overfueling big time.

Had my lambda after the cat go, and was only get best about 28average (Driving like grandad!) Now replaced an workin, im gettin 35average town driving that is!