DS3 THP155 Diagnosis Help

[Mde80]

Never buy a THP they said.. so I did!
Took it out for its first proper run and got an engine fault (Service light and text on the screen, not EML)

No codes. So I recorded a log of throttle, rpm, boost and trims. that sounds like I know what I'm doing.. I don't lol

It's not boosting and the LTFT is at 18%. I gave the data to ChatGPT and got a 'without a doub't response of PCV valve. If I take the oil filler cap off it chuffs oily smoke out.

The garage I bought it off says they will repair, but they're miles away and its a logistical nightmare. They've said they'll contribute to the parts cost. Can I be sure its the PCV?

I'm having trouble finding a reasonable quality (but not top dollar) rocker cover (Febi or Blue Print have been recommended) apparently stock is low and there's a price surge in the UK if CGPT is to be believed.

Any help mucho appreciated.

[mickthemaverick]

I have moved this to the DS section where you may get a better response.

[xantia_v6]

I rather doubt the PCV valve is the cause of your problem, and I am not familiar with any connection between the PCV valve and the Long Term Fuel Trim. A few years ago I bought a FEBI brand top cover for one of these, and what arrived was an apparently genuine PSA part with the PSA identification ground off!

Was the message like "Engine Repair Necessary" or something else?

[PaulC5]

Maybe explore returning the car and getting your money back. Otherwise get a full diagnostic to see what might be wrong but if you start fixing it yourself you might invalidate any warranty you have with the dealer you bought the car from.