Hi, I've had a persistent problem with my VRS where it'll go in to limp mode when driving slowly in first gear. It's completely intermittent, in the sense that it sometimes triggers and sometimes doesn't but the only factor In common I can highlight is it's always in first gear. 

 

The fault code 17705 is 'Pressure Drop between Turbo and Throttle Valve' however, I've done multiple boost leak tests, bought a brand new forge 008, which I serviced after to rule out, I've cleaned the throttle body, deleted the n249, n112 and SAI, replaced all the PCV hoses and today I tried another N75 Valve. 

 

I have recently had it remapped too which took it from a stage 1 map (which had the same issue) to a stage 2 map, so I can't imagine that it's a software fault.

 

Could anyone else help shed some light on this ongoing issue?

 

Thank you.

Who remapped it? I went through the same process as you, had The code and went through the motions, fitted a new dv as that is the subtext of that code. Turned out to be the remap, had it mapped by someone else and problem went away. In hindsight I should have taken it back, had map taken off and got money back, but I couldn't prove that was wrong until I'd had new remap if you know what I mean. Anyway, take it back to mapper and explain you've checked and replaced other possible causes so software is all that's left and tell him to take a look or take it off, see if it goes ok standard.

You may also find this useful re 008

http://www.audi-sport.net/xf/threads/forge-007p-or-008p.160567/

What spring is in yours? If yellow you could try a shim to preload it a little.

Dare I say you could also put your standard dv back in...

Bad Custom Code map did it for me on my old mkiv Golf Anniversary. Replaced all the boost & vacuum pipes, Y suction pump, DV, etc spent £££££'s. Remapper still  insisted the map wasn't the problem, then out of total desperation I had the Revo trial loaded in, & low & behold 17705 stopped.

This pretty much covers 17705. http://uk-mkivs.net/topic/10891-17705-the-saga-is-over-well-for-me-anyway/

Bad Custom Code map did it for me on my old mkiv Golf Anniversary. Replaced all the boost & vacuum pipes, Y suction pump, DV, etc spent £££££'s. Remapper still  insisted the map wasn't the problem, then out of total desperation I had the Revo trial loaded in, & low & behold 17705 stopped.

This pretty much covers 17705. http://uk-mkivs.net/topic/10891-17705-the-saga-is-over-well-for-me-anyway/

It's been remapped by two different people now, which makes me think it cant be a software issue. 

 

I also scanned block 032 and got the results 0.2% / -0.8%, so that almost certainly confirms there is no boost leak.

 

I'll try some more logging this weekend to see if I can see when the boost is dropped.

 

You may also find this useful re 008

http://www.audi-sport.net/xf/threads/forge-007p-or-008p.160567/

What spring is in yours? If yellow you could try a shim to preload it a little.

Dare I say you could also put your standard dv back in...

I've got the yellow spring in mine and it didn't come with any shims when I bought it mate. I'll try another next week some time hopefully, unfortunately I don't have the stock recirc valve available to me.

 

Who remapped it? I went through the same process as you, had The code and went through the motions, fitted a new dv as that is the subtext of that code. Turned out to be the remap, had it mapped by someone else and problem went away. In hindsight I should have taken it back, had map taken off and got money back, but I couldn't prove that was wrong until I'd had new remap if you know what I mean. Anyway, take it back to mapper and explain you've checked and replaced other possible causes so software is all that's left and tell him to take a look or take it off, see if it goes ok standard.

V12 Chip tuning mapped it for me, a reputable Manchester firm. Considering it did it before and after the second remap, I half doubt this is the problem. I'll be trying more stuff over the weekend which will give me a bit more information on it hopefully.

It's been remapped by two different people now, which makes me think it cant be a software issue. 

 

I also scanned block 032 and got the results 0.2% / -0.8%, so that almost certainly confirms there is no boost leak.

 

I'll try some more logging this weekend to see if I can see when the boost is dropped.

 

I've got the yellow spring in mine and it didn't come with any shims when I bought it mate. I'll try another next week some time hopefully, unfortunately I don't have the stock recirc valve available to me.

 

V12 Chip tuning mapped it for me, a reputable Manchester firm. Considering it did it before and after the second remap, I half doubt this is the problem. I'll be trying more stuff over the weekend which will give me a bit more information on it hopefully.

Wasn't there an issue with their previous map though with sketchy boost delivery? I'm thinking this is a software issue. A lot of these 17705 codes are down to that especially after boost leaks are ruled out.

Also, a new fault code appeared yesterday - DTC 16804 (Catalyst System; Bank 1: Efficiency Below Threshold) 

 

Could this be any relation?

Wasn't there an issue with their previous map though with sketchy boost delivery? I'm thinking this is a software issue. A lot of these 17705 codes are down to that especially after boost leaks are ruled out.

The previous was mapped using a manual boost controller, without the mbc it boosted to 12.5psi and went in to limp mode.

The previous was mapped using a manual boost controller, without the mbc it boosted to 12.5psi and went in to limp mode.

Saying that I'm still not convinced it was mapped before. It didn't really feel like it.