Question on BMW 3-Series E36 O2_Sensor

Hi there pelican staff. I'm living in Indonesia and have purchased a 1996 e36 323i with 2.5 single vanos. I have been experiencing low rpm bogging/hesitation. I have rebuilt the vanos system and changed out the cam and crank sensors and timed the engine accurately. I had a look at the exhaust manifold and cat. There appear to be no oxygen sensors pre and post cat. Unplugging the mass air flow sensor makes no variation in performance. There are to connectors on top of the fuel rail. Are these for the bank 1 and 2 sensors? Having looked it appears the plug bolts in the manifold are factory. My question is. Shall I replace the mass air flow sensor and forget about the o2 sensors. Or replace all 3..mass.and o2s. The car was assembled jakarta indonesia. One more note. Adding fuel manually to the intake cures the bogging which tells me that she's running lean..thanks for reading.

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[Nick at Pelican Parts]

I cannot offer much insight as I do not know what that vehicle came equipped with. You can check the basics, fuel, ignition and compression to start.

- Nick