Swapped S52 into M52 Z3, having a O2 dual bank issue (per tuner)

[parkerbink]

'97 My 2.8 M52 died I got an S52, had the 2.8 DME (index 11) flashed by Active Autowerke as I have their SC. After several rounds of tuning the car feels great but they say idle is lean and has needed a ton of added fuel.

Also, although bank 2 is tuned out it goes in & out.

Has anyone seen this?

[MrBurgundy]

What do you mean you have bank 2 tuned out?

Are you running one oxy sensor?

If it's leaning out it could be a intake issue rather than a DME issue.

[parkerbink]

Active coded bank 2 out on my DME, The 2.8 has 2 O2s, one pre cat, one post. The S52 had 3 (I believe) one at each header & post cat.

In my logs they say I need a ton of gas at idle to not be lean. Anywhere else the AFRs are fine.

The car is running like a train, feels great, not being hyper aggressive I chirp into every gear.

If they had not told me I would have thought I was done.

My thought is as long as it idles & is not stalling (it does and is not) then what difference does idle make? It is rarely idling & when it is there is no stress on the motor.

Do I really need to chase this & more importantly, do I need to spend another 600 on a Z3M DME & harness (let alone swap the entire engine harness)

[MrBurgundy]

Okay that makes sense then.. One pre oxy means one bank and two pre would be a two bank system for fuel trim

I agree, as long as the fuel trim isn't pinned (I think that dme is about +25) then I wouldn't stress it. Cuz it's correcting it.

[parkerbink]

Thanks, I'd like it to be perfect & had I known when the motor was out I'd most likely have done the harness, now it is a much bigger job & I am seriously tired of wrenching on this car, I have been since November.

Here's the motor.

[TobyB]

Me, I'd stuff an aftermarket wideband oxygen sensor into it, and keep an eye on things for a bit.

Because it 'oughta be all right' but a new S52's not an inexpensive proposition.

t

[parkerbink]

I have a PSB-1 AFRs are near perfect at high revs (10-11)

When I first installed it, the sensor was bad, Innovate replaced it.

https://vimeo.com/930071858

I have seen 7.7, can't find that picture.


Also, this is a new S52, has under 1k miles. :D

[parkerbink]

This happened today.