I own a 2002 110 Elegance hatch with 103k on the clock. I have owned this Octavia for nearly a year and I have always thought that the performance was lacking, especially compared to my wifes 100PD Bora, which leaves my Octy for dead...

Anyway, in a bid to try and cure the lackluster performance, over the past twelve months I have replaced the MAF and most recently last October, I fitted a recon turbo myself including cleaning out of the intake manifold and EGR, blanking the EGR on re-assembly. I thought the fitting of a new turbo would cure my problems, however disappointingly (and to my cost) there was little improvement.

In addition, although fuel economy is reasonable for a TDI, it is not outstanding and I struggle to get 50mpg overall per tank (working consumption out manually as the fuel computer is wildly inaccurate - between 5 and 8 mpg out!). Again no improvement was noted since the changing of the turbo. Compared to my previous 90bhp Ambiente, this was much better on fuel, regularly averaging 55+mpg.

I have had my Elegance scanned numerous times on VAG-COM and there are no codes stored to suggest any other issues.

The next thing I am thinking is that the CTS (on the ECU circuit) is misreading the engine temp causing fuelling issues. The dash gauge appears to work fine. The sensor is the original black one.

To drive the car it feels as though it is holding back, especially mid-range to top end and is noticable whilst overtaking when you need that mid range torque the most. I can only describe the feeling as when older carburetter petrol engines used to get 'choked up'. Would a faulty CTS cause these running issues?

I know that a new CTS won't break the bank but rather than shell out just under £30 for a genuine new one, I don't want to waste my money if my car does not need it and pursue other options.

Your views would be much appreciated

Dan

Can't really suggest a fix but can tell you how my car performs, it's a 1.9tdi 110 elegance also, it's a 03 with 89k. It is noticeably faster than the 90bhp and I have never got below 55mpg. I like to push the car at times as I travel over 25 miles to work and as I set off at 5am I often leave it late setting off my dad also has a 110 tdi on a 04 with 100k on the clock and his performs the same as mine, he often averages 65-68mpg as he drives like the pope!

Poor mpg is definitely one of the signs of a duff CTS and as they're dual-mode its possible to still get a sensible dash reading but for it to be telling the ECU the temperature is all over the place. If you don't want to shell out for a new CTS without being sure then you could always get a local member with VCDS to come and log what the ECU thinks the coolant temp is.

I only get around 53mpg out of my TDI 110 on a decent run, or around 45mpg around the town. If you get a new CTS and it improves your mpg, please post back and let us know.

Poor mpg is definitely one of the signs of a duff CTS and as they're dual-mode its possible to still get a sensible dash reading but for it to be telling the ECU the temperature is all over the place. If you don't want to shell out for a new CTS without being sure then you could always get a local member with VCDS to come and log what the ECU thinks the coolant temp is.

Thanks

Will get a check on VCDS re the readings of the engine temp and will buy a new sensor. Just wondering whether my performance issues are caused by overfuelling, hence the feeling the the car is 'choked up'.

Dan

Can't really suggest a fix but can tell you how my car performs, it's a 1.9tdi 110 elegance also, it's a 03 with 89k. It is noticeably faster than the 90bhp and I have never got below 55mpg. I like to push the car at times as I travel over 25 miles to work and as I set off at 5am I often leave it late setting off my dad also has a 110 tdi on a 04 with 100k on the clock and his performs the same as mine, he often averages 65-68mpg as he drives like the pope!

That's interesting as my 110 doesn't particularly feel noticebly faster or torquey than my previous 90! My turbo is definately boosting (you can really hear it 'whistle' since the new turbo I fitted), but I don't feel the benefit! It actually seems that the more I push it to the limit, the throttle response deteriorates....

Dan

I only get around 53mpg out of my TDI 110 on a decent run, or around 45mpg around the town. If you get a new CTS and it improves your mpg, please post back and let us know.

That is really poor for the 110.

That's interesting as my 110 doesn't particularly feel noticebly faster or torquey than my previous 90! My turbo is definately boosting (you can really hear it 'whistle' since the new turbo I fitted), but I don't feel the benefit! It actually seems that the more I push it to the limit, the throttle response deteriorates....

Dan

I never owned one but I test drove a 90 just before I bought the 110 is the 110 revved much more freely and got up to speed a lot fast and with more ease than the 90. I also had a 2.0 HDi 110 just before the octavia and the octy is much faster.

I never owned one but I test drove a 90 just before I bought the 110 is the 110 revved much more freely and got up to speed a lot fast and with more ease than the 90. I also had a 2.0 HDi 110 just before the octavia and the octy is much faster.

Something definately wrong with mine then!

Replace the black CTS as it will fail eventually. Genuine green VAG CTS is a must IMO, as cheap aftermarket ones usually fail quickly.

Might also be worth checking for vacuum leaks. I replaced all my flexi vacuum pipes a while back, and also found a split in the rigid pipe which supplies the brake servo.

Might also be worth checking for vacuum leaks. I replaced all my flexi vacuum pipes a while back, and also found a split in the rigid pipe which supplies the brake servo.

I checked all these when I changed the turbo, and all looked okay although the long one from the N75 valve to the turbo actuator felt a bit 'limp'.

For the record, I filled up today and the consumption worked out (manually) as only 47.5.mpg (although the fuel computer reckons it has averaged 55.7mpg!) :'(

Off to TPS I think for a new CTS to see if a new green one will improve things.....

Dan

I'm sure my CTS is green. Might have to double check tomorrow.

To those who reckon these mpg figures are bad - are you saying that based on manually calculating fuel consumption from full tank to full tank, or going on the display on the computer?

I'm sure my CTS is green. Might have to double check tomorrow.

To those who reckon these mpg figures are bad - are you saying that based on manually calculating fuel consumption from full tank to full tank, or going on the display on the computer?

Manual. I've compared the trip computer to manual tank yo tank and mine is only 2-3mpg out.

Maybe I need to shorten my right leg by an inch or two, or remove the lead from my boots

I didn't think that I drove the car that hard though. I can usually get over 30mpg out of the Porsche on a run, so I can't be that lead footed.

Just to keep you updated

I fitted new genuine green CTS on Sunday afternoon and I must say I have noticed a real difference in the performance of the car! Pulls much much better, engine feels smoother and generally more responsive. It even seems to start better and run smoother from a cold start (not that it was a 'bad' starter anyway).

So, early indications suggest that the fitting of a CTS has been worthwhile. Bit early to comment yet re fuel consumption as fuel computer is making similar readings to before, however this is approx 8mpg out at present.

Hopefully once the ECU has settled into the 'new' readings from the CTS I should hopefully benefit from better fuel consumption as well as performance (fingers crossed!)

Dan

I also replaced my CTS at the weekend with a Febi Bilstein unit from AVS. At the moment, as far as I can tell, no change in performance of fuel economy, so it looks as though my original was still OK. I will work out the mpg at the weekend when I fill up again.