Hi folks we seem to have a rash of later A6s and other models that have had remaps and a couple of years down the line get running problems, the later technology software for Euro 6 is far more sophisticated than Euro 4-5 ever was, the sensors it controls are very sensitive and run between very narrow thresholds to maintain minimum emission levels to satisfy European standards, if you add to the mix that they were developing the software up to ten years before Euro 6 it then begs the question how can a bloke with a van or a download off the internet best about two million Euros worth off research and god knows how many more millions in refining these systems, yeah it is easier on the old models as the software has been cracked and is available for public consumption, allied to the fact the manufacturers dont care about older software as its past technology and can be re written to suit the writers purpose, then we have the  fallout from newer maps such as increased temperatures throughout the engine which causes premature Turbo wear as well as injector wear as the ECU struggles to maintain its as built peramiters, then add the coding issues to make sure the average DIY mechanic and garages are constantly buying new and more sophisticated diagnostic machines to be able to affect repairs, the coding of major engine emissions components is to maintain a seamless repair protocol, therefore most of these cheaper maps will upset that balance.

A few years ago a neighbour bought his son a brand new Vauxhall Corsa so he could commute to university and back, six months in it just made it home, I read the car and could not find any running faults so we called it a day, four days later it went back to the dealer who after four hours called the dad and told him the cars ECU was knackered as it had been interfered with, finally JNR admits one of his uni friends had done a remap on the car three months before, two days later and a new ECU at £1700 plus fitting and coding, the car was back to as built and running like a dream, all that for an alleged extra twenty BHP, if you want fast, buy fast, one of the wires friends works as a software tech for an MOD manufacturer for guided missile navigation systems, I asked her if she could write a remap for modern cars and she said yes as long as she had access to the current software profile, [not available] and at least three years to get it trialed and a certificate of compliance.

Steve.

Completely agree Steve. With Euro 6 technology and the whole VAG diesel-gate saga, then you understand they were trying to build bigger, more powerful engines and trying to keep CO2 within emission levels.

Any kind of map will change the running characteristic of the car, just like EGR or DPF deletes. Somewhere further down the line, a fault will occur and usually it’s expensive.

If you want more power, then just sell the existing car and buy stock performance off the shelf. Usually the car will come with unrated turbo, better cooling, larger brakes, oil cooler, etc.

The remapping problem is why I am tending more and more to ask members if a faulty vehicle has been remapped. Many folk are happy to accept the extra performance while remaining blind to the increased wear, decreased reliability, and decreased durability it also brings.

Very informative Steve. Besides your sound advice, I think most people don't realise that tampering with the emissions systems is also illegal and voids insurance 

21 hours ago, spartacus 68 said:

Completely agree Steve. With Euro 6 technology and the whole VAG diesel-gate saga, then you understand they were trying to build bigger, more powerful engines and trying to keep CO2 within emission levels.

Any kind of map will change the running characteristic of the car, just like EGR or DPF deletes. Somewhere further down the line, a fault will occur and usually it’s expensive.

If you want more power, then just sell the existing car and buy stock performance off the shelf. Usually the car will come with unrated turbo, better cooling, larger brakes, oil cooler, etc.

Hi I can appreciate a thinking mans point of view, not because it is an agreement but because its based on sound thinking and knowledge of the pitfalls of this practice, I started to learn years ago when I got into tuning Minis, I was advised that cutting the inlet manifold from the exhaust manifold and fitting a go faster alloy inlet manifold was the way to go, smoother gas flow less heat, fine until the ambient air temp dropped and the fuel vapour was so dense is all you got was loads of white smoke, turns out the manifolds were joined to create a hot spot in the plenum chamber on the inlet manifold to vaporise the fuel on cold days, so I ended up paying a fortune for a water heated inlet manifold, new thermostat housing and about a couple of yards of heat proof hose to plumb it in, my point being that even with that sort of primitive technology you could still run aground throwing away parts the car was built with, they dont fit these systems for fun, go forward a couple of decades and you really are dancing with the Devil trying to alter it, a very wise Ford technician once said, if you can reasonably gain another forty break horsepower from a simple remap do you honestly think the manufacturer would leave those gains on the table for someone else to make money out of, NO, they would be producing the remaps themselves and selling them at a premium, [Manufacturer Approved], the reason they dont is because these things cause problems of which they already have plenty.

Steve.

58 minutes ago, Stevey Y said:

 if you can reasonably gain another forty break horsepower from a simple remap do you honestly think the manufacturer would leave those gains on the table for someone else to make money out of, 

I have tried that argument but it falls on deaf ears at the prospect of extra performance for peanuts.

2 minutes ago, cliffcoggin said:

I have tried that argument but it falls on deaf ears at the prospect of extra performance for peanuts.

Hi Cliff, bang on but how do you educate people, you can't and we are just a miserable tribe of old Duffers until it all goes horribly wrong, then they are back demanding answers to problems of their own making.

Steve.

On 10/6/2025 at 5:06 PM, Stevey Y said:

a very wise Ford technician once said, if you can reasonably gain another forty break horsepower from a simple remap do you honestly think the manufacturer would leave those gains on the table for someone else to make money out of, NO, they would be producing the remaps themselves and selling them at a premium

An interesting comment given that Ford use an identical 2.0ltr diesel lump in various cars with 120, 150 and 180bhp depending on what the buyer want's to go for. Same with the 1.5 petrol ecoboost lump, 120, 150 and 180bhp. Add on to that that manufacturers have to tune their cars based on the assumption that the owner is going to forget about changing filters and run on the worst available fuel on the planet while still being able to survive for the length of the warranty period.

I've remapped my own cars over the years - Peugeot 406 coupe 2.2hdi that went from 136bhp - 180bhp with a basic flash tune, Mk4 Ford Mondeo 2.5t was Bluefin mapped from 218bhp to 296bhp, Nissan Skyline R33 GTSt 2.5t standalone ecu and dyno tuned went from 250bhp to 444bhp, a different Nissan Skyline R33 GTSt 2.5t with a piggy back ecu (emanage ultimate) that I road mapped myself went from 250bhp to 475bhp.

All of these cars were run between 1 and 14years with these maps and never caused an issue. The Celtic Tuning map I've had on the Q5 for over a year has also been faultless.

Can a remap cause excess wear compared to unmapped? I'd say yes, but not to the excesses that are being professed here, not if the remap is actually a GOOD one. I've seen a few people on here talking about "tuning boxes" that plug in between the AFM or the FPR and the ECU and they are garbage. But an actual remap of the ECU changing boost pressure, fuelling, ignition timing, supplied by a reputable tuner is no more dangerous to your car than an OEM tune. Just look at Mountune, they were offering remaps on Fords that were approved by Ford and didn't affect the Ford warranty. This Ford dealer still offers warranty backed services  https://www.foraymotorgroup.co.uk/ford-mountune/

 

1 hour ago, Mark M. said:

An interesting comment given that Ford use an identical 2.0ltr diesel lump in various cars with 120, 150 and 180bhp depending on what the buyer want's to go for. Same with the 1.5 petrol ecoboost lump, 120, 150 and 180bhp. Add on to that that manufacturers have to tune their cars based on the assumption that the owner is going to forget about changing filters and run on the worst available fuel on the planet while still being able to survive for the length of the warranty period.

I've remapped my own cars over the years - Peugeot 406 coupe 2.2hdi that went from 136bhp - 180bhp with a basic flash tune, Mk4 Ford Mondeo 2.5t was Bluefin mapped from 218bhp to 296bhp, Nissan Skyline R33 GTSt 2.5t standalone ecu and dyno tuned went from 250bhp to 444bhp, a different Nissan Skyline R33 GTSt 2.5t with a piggy back ecu (emanage ultimate) that I road mapped myself went from 250bhp to 475bhp.

All of these cars were run between 1 and 14years with these maps and never caused an issue. The Celtic Tuning map I've had on the Q5 for over a year has also been faultless.

Can a remap cause excess wear compared to unmapped? I'd say yes, but not to the excesses that are being professed here, not if the remap is actually a GOOD one. I've seen a few people on here talking about "tuning boxes" that plug in between the AFM or the FPR and the ECU and they are garbage. But an actual remap of the ECU changing boost pressure, fuelling, ignition timing, supplied by a reputable tuner is no more dangerous to your car than an OEM tune. Just look at Mountune, they were offering remaps on Fords that were approved by Ford and didn't affect the Ford warranty. This Ford dealer still offers warranty backed services  https://www.foraymotorgroup.co.uk/ford-mountune/

 

Hi I think you missed the point, or maybe I did not explain myself properly, what I was referring to was the amount of posters on here that have had an off the peg remap done by their brother or some local Herbert with a van and a laptop and not as you pointed out a proper remap, they then have problems related to what they have mapped out, fact, mapping out EGRs will raise engine cylinder head temperatures, fact, upping boost pressure on a turbine will cause premature wear on the unit, I have a contact at Essex Turbos who would be quite happy to explain about the rash of over mapped Focus RS that were running well over 400bhp that were consistently shredding intake impellers due to overspin, the turbo was big enough but never designed for that type of boost requirement, Nissan are a completely different as the engines are built and balanced to a very high standard to accommodate the local markets desire for More and more power, made me smile when you mentioned Ford 2.0 engines, having spoken to a Ford engine tester on the track at Dunton he explained that if you wanted 180bhp out of a DW10A forget it it would not take the increase from 140 bhp -180 bhp without destroying something, as power demands increased PSA  were required to strengthen elements within the engine to cope with the extra power hence DW12 C and onwards until no reliable power gains were achievable, then they swapped to the DW12 which started with 175 bhp and by the end of production ended up with 200 bhp that was as far as the emissions/ fuel consumption allowed, at no point did he mention that Ford were planning to produce any model with no cat or DPF, which brings me to the point of when a lot of these companies delete the lot you have to sign to say the vehicle is only going to be used on private roads because they dont meet the legal emissions standards, I also note the other maps you mention are quite mild by manufacturer standards which in the case of Mountune/Ford are within the prescribed boundaries of the built in reliability factors, the other more extreme tunes are dealt with at Mountunes other establishment over the back of me in Hutton where they tear the engines down and beef up everything, these are classed as racing engines and I would assume therefore are not road legal, in essence what I am driving at is people buy these cars often quite old and have a cheap remap but can't afford to fix them when they go wrong due to age and milage.

Steve.

Hi I think you missed the point, or maybe I did not explain myself properly, what I was referring to was the amount of posters on here that have had an off the peg remap done by their brother or some local Herbert with a van and a laptop and not as you pointed out a proper remap, they then have problems related to what they have mapped out,

 

"Off the peg" remaps is exactly what I ran on the Mondeo and the Peugeot, the later with the DW12C 2.2 HDi engine.

But no, you just branded "remaps" as the problem when I think in reality it's tuning boxes that are the problem.

 

 fact, mapping out EGRs will raise engine cylinder head temperatures,

 

Fact, having an EGR increases the soot content in the oil leading to higher ware of the lower control rings on the piston by about the same amount as the extra heat from removing the EGR will affect the top compression ring.

 

fact, upping boost pressure on a turbine will cause premature wear on the unit,

I have a contact at Essex Turbos who would be quite happy to explain about the rash of over mapped Focus RS that were running well over 400bhp that were consistently shredding intake impellers due to overspin, the turbo was big enough but never designed for that type of boost requirement,

 

Fact, this is why compressor maps are used to keep a turbo within a safe operating window. Upping the boost pressure too far outside that window will cause wear and/or failure, but increasing it while staying in that window will not directly cause any issue.

 

Nissan are a completely different as the engines are built and balanced to a very high standard to accommodate the local markets desire for More and more power,

made me smile when you mentioned Ford 2.0 engines, having spoken to a Ford engine tester on the track at Dunton he explained that if you wanted 180bhp out of a DW10A forget it it would not take the increase from 140 bhp -180 bhp without destroying something, as power demands increased PSA were required to strengthen elements within the engine to cope with the extra power hence DW12 C and onwards until no reliable power gains were achievable, then they swapped to the DW12 which started with 175 bhp and by the end of production ended up with 200 bhp that was as far as the emissions/ fuel consumption allowed,

 

DW10 is the PSA/Ford duratorq engine that Ford sold in the Mondeo, SMAX and Galaxy with 120bhp, 150bhp and 180bhp with only the map being different, I know as I looked into it when my MIL was getting her new Galaxy back in 2019. Same as every other car manufacturer has at one time or another.

Not sure why you bring in the 2.2 DW12 as I was merely highlighting your quote from a Ford tech that a manufacturer wouldn't leave horsepower on the table when Ford clearly did/do.

 

at no point did he mention that Ford were planning to produce any model with no cat or DPF, which brings me to the point of when a lot of these companies delete the lot you have to sign to say the vehicle is only going to be used on private roads because they dont meet the legal emissions standards,

 

No manufacturer is going to do that now are they, but when it comes to the MOT and the car fails spectacularly the MOT tester can either look the other way for a few quid and risk his entire career or just fail it which I've seen more than a few times.

 

I also note the other maps you mention are quite mild by manufacturer standards which in the case of Mountune/Ford are within the prescribed boundaries of the built in reliability factors,

 the other more extreme tunes are dealt with at Mountunes other establishment over the back of me in Hutton where they tear the engines down and beef up everything, these are classed as racing engines and I would assume therefore are not road legal, in essence what I am driving at is people buy these cars often quite old and have a cheap remap but can't afford to fix them when they go wrong due to age and milage.

 

No, a "racing" engine IS road legal. I've personally built a fully forged (crank, rods pistons, flow matched and ported head etc) RB25DET with an aftermarket HKS turbo and it was fully road legal and within emissions standards. I also have a good friend that works for Devil Developments and they churn out 700-800hp Focus's that are road legal. Mountune maps are also "off the peg" as you put it.

9 hours ago, Mark M. said:

Hi I think you missed the point, or maybe I did not explain myself properly, what I was referring to was the amount of posters on here that have had an off the peg remap done by their brother or some local Herbert with a van and a laptop and not as you pointed out a proper remap, they then have problems related to what they have mapped out,

 

"Off the peg" remaps is exactly what I ran on the Mondeo and the Peugeot, the later with the DW12C 2.2 HDi engine.

But no, you just branded "remaps" as the problem when I think in reality it's tuning boxes that are the problem.

 

 fact, mapping out EGRs will raise engine cylinder head temperatures,

 

Fact, having an EGR increases the soot content in the oil leading to higher ware of the lower control rings on the piston by about the same amount as the extra heat from removing the EGR will affect the top compression ring.

 

fact, upping boost pressure on a turbine will cause premature wear on the unit,

I have a contact at Essex Turbos who would be quite happy to explain about the rash of over mapped Focus RS that were running well over 400bhp that were consistently shredding intake impellers due to overspin, the turbo was big enough but never designed for that type of boost requirement,

 

Fact, this is why compressor maps are used to keep a turbo within a safe operating window. Upping the boost pressure too far outside that window will cause wear and/or failure, but increasing it while staying in that window will not directly cause any issue.

 

Nissan are a completely different as the engines are built and balanced to a very high standard to accommodate the local markets desire for More and more power,

made me smile when you mentioned Ford 2.0 engines, having spoken to a Ford engine tester on the track at Dunton he explained that if you wanted 180bhp out of a DW10A forget it it would not take the increase from 140 bhp -180 bhp without destroying something, as power demands increased PSA were required to strengthen elements within the engine to cope with the extra power hence DW12 C and onwards until no reliable power gains were achievable, then they swapped to the DW12 which started with 175 bhp and by the end of production ended up with 200 bhp that was as far as the emissions/ fuel consumption allowed,

 

DW10 is the PSA/Ford duratorq engine that Ford sold in the Mondeo, SMAX and Galaxy with 120bhp, 150bhp and 180bhp with only the map being different, I know as I looked into it when my MIL was getting her new Galaxy back in 2019. Same as every other car manufacturer has at one time or another.

Not sure why you bring in the 2.2 DW12 as I was merely highlighting your quote from a Ford tech that a manufacturer wouldn't leave horsepower on the table when Ford clearly did/do.

 

at no point did he mention that Ford were planning to produce any model with no cat or DPF, which brings me to the point of when a lot of these companies delete the lot you have to sign to say the vehicle is only going to be used on private roads because they dont meet the legal emissions standards,

 

No manufacturer is going to do that now are they, but when it comes to the MOT and the car fails spectacularly the MOT tester can either look the other way for a few quid and risk his entire career or just fail it which I've seen more than a few times.

 

I also note the other maps you mention are quite mild by manufacturer standards which in the case of Mountune/Ford are within the prescribed boundaries of the built in reliability factors,

 the other more extreme tunes are dealt with at Mountunes other establishment over the back of me in Hutton where they tear the engines down and beef up everything, these are classed as racing engines and I would assume therefore are not road legal, in essence what I am driving at is people buy these cars often quite old and have a cheap remap but can't afford to fix them when they go wrong due to age and milage.

 

No, a "racing" engine IS road legal. I've personally built a fully forged (crank, rods pistons, flow matched and ported head etc) RB25DET with an aftermarket HKS turbo and it was fully road legal and within emissions standards. I also have a good friend that works for Devil Developments and they churn out 700-800hp Focus's that are road legal. Mountune maps are also "off the peg" as you put it.

Hi you obviously have a problem with opposing opinions which I can understand if you are an avid fan of this particular form of tuning but in your final paragraph you give a whole list of mechanical changes you did to get the high horsepower you desired, therefore would you consider that kind of mapped horsepower a viable option on a standard engine and yes Mountune maps are off the peg but Dave Mountain had to present each proposed map for approval to Ford Tech at Dunton to assess the suitability of such under warranty.

Steve.

 

On 11/6/2025 at 8:17 PM, Stevey Y said:

Hi you obviously have a problem with opposing opinions which I can understand if you are an avid fan of this particular form of tuning but in your final paragraph you give a whole list of mechanical changes you did to get the high horsepower you desired, therefore would you consider that kind of mapped horsepower a viable option on a standard engine and yes Mountune maps are off the peg but Dave Mountain had to present each proposed map for approval to Ford Tech at Dunton to assess the suitability of such under warranty.

Steve.

I could say exactly the same about you.

I have no problem with differing opinions, that's what forums are for. But at the same time, if I see an opinion that I do disagree with I will comment based on my hands on experience, if the other party's to that conversation don't want to hear it or are unable to accept a different point of view then that's prerogative.

I said I have personally built an RB25DET..... I never said it was mapped by me, and I never said it was even FOR me. That particular engine was running a PowerFC and I believe running around 800bhp last I heard. Stock RB25's have been known to run around 500bhp with a suitable turbo but the engine internals are on a bit of a knife edge at that point. Totally stock you would be at around 320-330bhp.

Gents.

While I am glad to read of opposing views on the matter, particularly as I have no personal experience of re-mapping, the arguments are starting to become personal so I am locking this topic.