Running Lean, nearly stock, wtf.
 

I have a 1996 B18B1 in my 1992 Civic CX hatch.

Intake, and high-flow cat, and 2.25 cat-back exhaust.

Stock header, stock motor.

I just got my wide-band installed, and for a while now I've noticed that the car 'breaks up' a little at about 5700RPM untill redline. (wide band is just behind my ebay high flow cat, so its basically just a test pipe and has no affect on the wide band)

So I finally did some runs with the wide-band and found out my car is leaning the piss out at 5700RPM *pegs my wide-band at 16.8*

Ideas? Solutions?

Stock CX fuel pump with 110K on it, motor should only have like 74K on it.

Re: Running Lean, nearly stock, wtf.
 

A high-flow cat is still a cat, install your wideband before it for accurate readings.

Re: Running Lean, nearly stock, wtf.
 

There is NO material in exhaust path of the pipe, its nothing but a resonator.

Regardless, a 16.8 spike (while the car is loosing power) is more than just a coincidence.

Re: Running Lean, nearly stock, wtf.
 

Why don't they just call it a test pipe then?

Anyways, the lean condition is most likely being caused by the ignition breakup. The unburned oxygen in the exhaust will cause the wideband to display lean. Fix the ignition problem and your AFR should get closer to where you want it.

Re: Running Lean, nearly stock, wtf.
 

when I say 'breaking up' I don't exactly mean its the ignition, I just feel like its loosing power up top. I apologize if i didn't explain that well enough.

Re: Running Lean, nearly stock, wtf.
 

do a tune up on that ------- thing. cap, rotor, stock plugs, stock wires. How is it in the rest of the rpm range? is it the ls obd1 ecu? is it chiped? need more info.

Re: Running Lean, nearly stock, wtf.
 

Stock.

Motor is a 96, Car is a 92 (therefore converting the motor to OBD1 through use of stock wiring)

OBD1 PR4 ECU, Not chipped.

Rest of the RPM's it pulls like a raped ape, Spins into second with P205's on it.

Re: Running Lean, nearly stock, wtf.
 

sounds like it needs a tune up to me

Re: Running Lean, nearly stock, wtf.
 

I read a few articles stating that the CX fuel pump doesn't provide adequate flow for the B18.

Re: Running Lean, nearly stock, wtf.
 

let me guess never changed your fuel filter.