PO172 Running too Rich

[Bundle Bear]

Hi Guys

This is my first post, I have a heavily Modded MCS R53, I cannot get it through the MOT as my emissions are really high, I had the fault code PO172, which I know means it's running too rich, however I am struggling to find out why, I am looking for some advice, this is what I know and have tried

1) Its not the CAT, as it's a pre CAT issue (according to a BMW technician)
2) Tried mapping it out, didn't work
3) Could be an injector issue? Running 440's
4) Could be a sensor issue, can any one tell me how many sensors to check, are there two, the lander sensor and one by the Cat
5) Could be loose wiring to a sensor?

Is there anything else I can check, I am dying to get my car back on the road, but cannot afford to just keep chunking money at it as a wild goose chase.

Any help would be much appreciated. If it helps my performance mods are

Smaller Pulley
Lighter Crank wheel
Stage 4 head
Shrick Cams
Uprated 440 Injectors
Uprated Intercooler
Sports Manifold
High Flow Cat
Sports Exhaust
Sprint Booster

These are all the bits that I think could be relevant, the rest is smaller items

Cheers

[Snowie]

The only way I could get my GP with similar mods through the MOT was to change it back to 380 cc Injectors --- passed with flying colours.

The 440s with Shrick cam and big valve head means far too much fuel on idle and fast idle tests. The guys at Mininmotorsportcentre (Tony Franks & his team) had never seen an MOT test so rich with the 440's

[Bundle Bear]

Thanks Snowie

I was thinking about that, I was told though that the normal Injectors could not handle the setup and hence the upgrade. Unfortunatley, I don't have the originals, so it will mean buying a set of 380's. Are these stock injectors? If this is the fix, then the 440's are a bit of a con!!!

[Bundle Bear]

Also I read that 380's can only support running up to 220 hp, evening running crazily rich I'm getting 249hp and should be running over 260 hp, which is the minimum I was lead to expect my package would deliver, although I may have fallen foul of over HP estimates

[Snowie]

The GP is running 260 BHP and uses an AFPR and STOCK map with the 440s

The 380s are standard JCW / GP injectors and yes at 260 they will be beyond their safe range and you run the risk of beeing too lean at the top end. However to get you through the MOT they will be fine.

[Bundle Bear]

I; see what I can sort out and advise back idf it gets through and whether I can run it at an acceptable level, currently it is way too rich

[Bundle Bear]

Ok this has finally been sorted after months of (bad tuner advice) advice and roughly 1.5K of various parts and garages time. Typically it was something that cost very little to sort, but thanks to John from GTT and Lee from TS cars for sorting it out (thanks Snowie for the advice too). Turned out the AFPR needed to be adjusted to reduce the boost and pressure. Its going for its MOT on Monday (again) and should pass this time, then its off to the rolling road next week to see what we are pushing, but from what I hear from Lee its savage!!!!!!