OK, another S50 question, 20.5# injectors...

[madsedan]

The shop rebuilt the motor last week and used M42 20.5 injectors on an otherwise stock S50 build running stock software.
Today I get it inspected and the N02 is good, low, but the C02 is crazy high, the cat is obviously working ok as indicated by the lower N02 but its running way rich.

Advice? There a chip I can pick up reasonably cheap for these injectors without droppig another $300-400 on 3 1/2 hfm and intake?

[328ijunkie]

Well obviously its the injectors. Put stock ones in there or get a chip. You dont have to get a 3.5" MAF for all tunes.

[madsedan]

OK update....
Shop finished the exhaust last weekend, 2 to 1 flowmaster going to 2 1/2" mandrel bent pipes with magnaflow high flow cat, straight through muffler.
They also tried chasing down the idle and hesitation issues and did a few other things...
-swapped in 17.5# injectors
-new cam position sensor
-checked cam locations
-swapped ECU with another red label with stock chip
-new O2 sensor and wiring harness
-checked compression and all is well from the rebuild, 195-205

Everything is drastically improved, throttle response is great, good power/pull, still not feeling the vanos switch over like I remember in my old M3's, BUT, in neutral its still rough idle, bouncing around, and will throw a CEL after 15-20 seconds without throttle input. When it blows the CEL usually a WOT run in gear over 3,500 will turn it off.

When I went back to get the emissions tested again today the Co2 is way low, well within range, but the No2 is way high, like the numbers did an exact flip from the last time.

Getting frustrated, looking for ideas, any ideas on stuff to check now? Would a vacuum leak somewhere cause this kind of behavior? No2 means its running lean and has a high cylinder temp right?