03 325i square 02 sensor plugs?

[spyderg0d]

I have apparently the oddball manufacture 03 325i that has square 02 sensor plugs for precat sensors. The problem is I got my full set of 02 sensors months ago and didnt bother to check if the plugs matched and obviously cant return them. I simply havent ever seen square plugs on these before. Is it ok to splice them in, or are they not compatible? Are the post cat sensors the same scenario as well? Thanks for any input ahead of time gentleman.

[MarcoZandrini]

Are you the original owner of the car? Does the car have the M56 engine? Go to bimmer.work and enter the last 7 characters if thr car’s VIN. That’ll tell you if the car has the M56 engine. That engine is part of the super low emissions vehicle package. The fuel pump is part of the fuel tank so it can’t be replaced separately. If it’s an M54 engine, which the vast majority of E46s have, someone replaced the normal sensors with some weird sensors.
If the engine is an M54, you need to buy Bosch (and only Bosch) direct replacement sensors. Label the connectors which reside under the black plastic cover on the top of the engine.

I googled the part # for the sensor. All of the pictures from reliable sites that specialize in bimmer parts show a typical sensor with 6 lands. That is, those sensors in your car are not Bosch sensors. Here’s an example:

https://www.turnermotorsport.com/p-3...probe-e46-m56/.

[spyderg0d]

It's an m54 for sure. I replaced the engine with bad crank bearings when I bought the car for a lower mileage well working one. I noticed while looking at several e46 in junkyards, the m52 e46 have round 02 sensor plugs. 04 and up have round sensor plugs.. my car... does not. Why must it be bosch?

[spyderg0d]

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[spyderg0d]

This is part of a converter replacement. 1 converter simply fell apart when I replaced the engine awhile ago. Since then the 02 codes have come for both pre and post. I figured of just get cats and 02 sensors and throw it all in at once.

[randy72877]

Square connector with 6 wires is wide band o2 or AFR sensor used in later models. Early cars had standard o2 sensors with 4 wires and a round plug.

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[dhurley34]

Was the harness replaced at any time to your knowledge? I've never seen the wiring going to the coils exposed.

[spyderg0d]

I don't have any issues with misfires or coils, so it wouldn't matter.

[dhurley34]

Couldnt care less of you're having misfires. Was asking in an attempt to find if the engine harness has ever been replaced.