Boost not breaking 0.6bar, even in Sport Plus using launch control. Could diverter valves be causing a leak? If so, would a leak be consistent? It jumps to 0.6bar and stops... not below or above.

 

Get something to pull the error codes thrown. Let us know...

 

I wish... no codes on my reader

 

Sorry, can’t help with boost problem but I agree with @jzchen. Fault code reader is very helpful if you plan to keep the car and do any DIY. I started with Durametric Pro and just recently got set up with a PIWIS 2 (dealer level tool).

PIWIS 2 works on cars up to 2017. After 2017 need a PIWIS 3. Of course, it’s a clone from China but it can now be had at an affordable price. I wouldn’t waste my time with any other tool now. Would likely pay itself off with one trip to the dealer.

If interested, check out:

https://www.planet-9.com/threads/piw...achine.238021/

Good luck and let us know how you make out.

 

I have lots of experience with something like this. Either codes have not been thrown yet or the reader is not reading already thrown codes. The code reader at AutoZone (cheap INNOVA) failed miserably on a friend's Mercedes E350, but the $40 Autel unit I got at Walmart found three pertinent codes...

Without the PIWIS (3 in my case) I saw the codes but was throwing parts at it. BUT you don't need to buy one if your current reader is trustworthy to read codes. All drivability codes should be readable because OBDII laws trying to protect the environment/fuel waste/pollution control.

​​​​​​All I need is the code and model and I can pull up the guided fault finding. Interestingly I looked up my initial codes that I was seeing a long long time ago, P1027 and P1024. They both first point to the FPS, and second possibility HPFP. If I had gone directly to buying the PIWIS I probably would have already returned the money I spent on the PIWIS by NOT replacing the HPFP in the first place.

I hope codes show up soon for you so I can try to find them for you...

 

I dont have piwis ii or iii, but I do have a Porsche/VW/Audi reader and that isn't throwing any codes, nor am I getting a CEL which I would expect if there was a legitimate boost leak as the air/fuel ratio would be off.

Thanks for the input though, this is why Im asking It's a very odd circumstance.

 

Did this just happen after you replaced the diverter valves? Have you tried putting the stock valves back in to see if you get more boost?

 

Yep, I was thinking it may be the diverter valves but it doesnt make logical sense to me... they are just diverting airflow, not restricting it, right? It would throw a code if the MAF sensor was reading a different air mixture. Would the spring strength cause an issue if it if were too strong/weak?

 

Also havent replaced it yet - havent had time to get it back on stands since doing a rally on Saturday.