M20 2.7i pinging /or stutter after 4krpm

[e30m20TurbO7]

I have a pinging or a stutter after 4000 rpm when I gir it the beans. When I keep it below 4k it drives fine till I punch it.
I don't have my o2 sensor hooked up right now because the wires are frayed on the the connector so I need to splice a new connector in.
The car is a 318is with a m20 swap with a bav auto chip
Using original fuel filter. And I'm running a new 318is pump
The pump is the same but the housing is different so that explains difference in part numbers.
Need some suggestions
I have a check engine light on. Running a 318 cluster

[kistler#7]

Do not run the car anymore until you have an o2 sensor, especially with new management. Finish your swap then drive it

[Gregs///M]

The 318 fuel pump also provides a lower pressure than required by the M20 motor i think. Might wanna check the bentley manual to see the nominal fuel pressure of the 318 vs the 325i.

I know for a fact that the motronic 1.1 M20 requires 43psi at idle.

[squidmaster]

The 318i system (late model at least) is 3 bar. Having a fuel pressure gauge hooked up will let you see if that is your problem.