Power loss after 421 installed

[Naz-b23]

Little help plz


I installed a 421 manifold on my micra and it seems to lack power until 3500-4000rpm then the power and torque kicks in like a basatrd all the way to 8000rpm

I have a 421 installed with a 1and 3/4 inch pipe with middle box from centre to back

Before i had a 4-1 manifold with 2inch from centre to back and that had more power from start to finish

Plz help also i have lambda sensor bank 1 disconnect can that cause a problem

Please help there is alot more torque but it lacks power sometimes it feels like the clucth is slipping but its not because i put a new 1 in

 

[Agent_Sm1th]

You will run very rich without that first sensor disconnected I would have thought. The first sensor checks the air/fuel ratio. The second just checks the cats working.

 

[Naz-b23]

I have a flat spot u reckon thats what causing it

 

[frank]

the lambda is fitted for emissions purposes, and the ecu will ignore the lambda and run open loop when booted, the dia of the primaries on that 4 into 1 were more suited to a CG engine naz