Ses p1093

[sidct]

Hello everyone: I have a recurrent problem with my car, 330Xi 2002 with 126000 miles that has the check engine light on. The code is P1093 (Pre-Catalyst Fuel Trim Too Rich Bank 2) I have checked & cleaned the MAF sensor, the O2 sensors were replaced at 100K as well as all the regular services etc. There are no other codes. I have erased the code couple of times and it comes back within 10 miles of driving. The car starts without any problems drives well with smooth acceleration etc. any clues ??? suggestions ???

[bmwdave37]

my first guess would be that you need a new air meter.

my second guess would be a failed fuel pressure regulator.

my third guess would be leaking injector.

[bkentopp]

Maybe new charcoal canister

maybe a new charcoal canister, sometimes can cause rich mixtures

[sidct]

I am still puzzled as to why only Bank 2 (cylinder 4,5,6) be affected. The park plugs appearance is normal and similar in all cylinders. Fuel consumption is excellent ( ie 23 to 25 MPG). My reasoning (?? faulty) regarding Fuel pressure regulator,fuel tank venting and MAF sensor is that both banks should throw the same code ???
Leaky fuel injector : how to check this out

MAF was the culprit indeed. The measured air mass in gms/sec does not change with throttle opening, it stays at 3.65gms/sec. Thank you all for the input. I measured it using OBDcom software which measures and graphs generic obd2 data. Logically it is still hard to explain why only one bank ( ie bank 2) was running rich??

[milestone707]

hey sidct,


Did you ever get to figure out the cause of the P1093? I am having the same issue you were having...Im thinking I need to replace the MAF??



Thanks

milestone707

[sidct]

hey sidct,

Did you ever get to figure out the cause of the P1093? I am having the same issue you were having...Im thinking I need to replace the MAF??

Thanks

milestone707

It turned out to camshaft sensor, diagnosed by the dealer, it did cure the issue and no more CEL, cost $450. I still cannot understand how and why of it.

[henryki]

Bumping a super old thread but I'm getting this as a pending code every 500-1000 miles in my 02 530i, I have a brand new MAF, valve cover gasket, intake boot, throttle body gasket, intake manifold gasket, PCV system, spark plugs, fuel filter W/built in pressure regulator, fuel pump, new vacuum lines from the EGR to the back of the intake manifold, intake manifold vacuum plugs (at the very back of the manifold), and brake booster vacuum hose. Any thoughts? I think I may have went above and beyond with my car and vacuum related issues haha

[Eaglesail]

No, just observing this postings...I use a propane torch, unlit, and wave it around vacuum hoses. If I hear a rise in engine rpm...gee, I guess there might be a leak. Vacuum hoses do fail.....at least, it should be a first order for check!

[TonyAngel]

Did you do all of that stuff chasing this code? First order of business should always be to run a scan with a bmw scan tool.