Spotting a chipped car - Blurred
There seems to be loads of companies offering performance chips or tuning boxes for Diesel cars, which suggest to me that there must be quite a few diesel cars out there with these chips or tuning boxes installed.

If I were wanting to buy a diesel car is there an easy way to spot that it has had one of these devices installed?

The tuning boxes can easily (so I am told) be taken off so how would I as a buyer figure out if a car has been subject to use with one of these power enhancement mods?

I wouldn't want to buy a car that has had one of these mods as it has undoubtably been put under greater strain than a non modded car.
I realise that these devices utilise the safety margin these engines have but I would still prefer an unmolested example.

The value of a car that has had one of these devices is surely less than an unmolested example but unless there is an easy way to spot that it has been deinstalled the buyer will be none the wiser and thus paying over the odds. If it has a tuning box still installed you would? be able to spot and thus offer less for it.

With more and more of these mods being sold, is buying a diesel becoming more fraught with uncertainty?

Thoughts appreciated.
Spotting a chipped car - Sooty Tailpipes
You would need to look inside the ECU, but there may be evidence on the outside of bent tangs or ripped warranty void if ripped labels.
Spotting a chipped car - apm
Some engines can be chipped without a chip. The VW 1.8t, for example, can be reprogrammed using the diagnostic port, leaving no evidence. Only way to know is by rolling road/ comparing with a certain non-chipped example of the same model. Bear in mind that most of these engines are well capable of handling the extra power- it's usually the rest of the car that can't!

Dr Alex Mears
Seat Leon Cupra
If you are in a hole stop digging...unless
you are a miner.
Spotting a chipped car - PoloGirl
Advance warning... I don't know what I'm talking about here...

Bloke I live with has been a little bit screwed over his new company car (they introduced a new policy just as he was about to order his A4, cutting the amount he was allowed to spend) and has finally settled on the Tdi Passat Sport whateveritscalled, which I think is very nice but he's understandably miffed over.

He wants to get it reprogrammed to increase the Bhp by one of those companies who advertise that it's completely undetectable. Question is... is it? And when it goes in for a service and gets plugged into their computers, wont they be able to spot it?

Spotting a chipped car - Wally Zebon
>>when it goes in for a service and gets plugged into their computers, wont they be able to spot it?

Not necessarily. If its a "good chip", then it will be undetectable to the makers diagnostics and the only way to tell will be via a rolling road or comparing the code within the chip.

I know this because I've had mine done and my dealer couldn't tell the difference.

Spotting a chipped car - Altea Ego
You can always tell if the chip has been changed. The dealer wont always look, or notice, or even know where to look but they could always tell if they wanted to look hard. Its called a checksum. If you change any of the data in a chip, the checksum will change. If there is any update to the chip required, the new update may not load because the checksum will be wrong. Insurance investigators can and do check for unauthorised chip upgrades.

As far as your mate goes PG, if the leasing comany find out they will hang him. Not his car, not allowed to do it, not insured for the car, big trouble if caught.
Spotting a chipped car - Altea Ego
Have to add here, that the device plugged into the ODBII port, (the one favoured for the VW) does not change the contents of the chip, and when unplugged from the port leaves no telltale evidence it was ever there.
Spotting a chipped car - Godfrey H {P}
Very dodgy PG. The OE manufacturer can plant all sorts of ways of checking if the chip is non-standard if they wished to with dealer diagnostic kit. Which manufacturers have or not is another matter. Detection could lead to big trouble as described above not to mention what would his employers view be.

Value my car