varjag

iTrader: (1)

I just bought 98' formula a couple of weeks ago and basically doing some maintains routine (oil, fuel filter, spark plugs and wires etc) and finally I get to the point when I stop by local autozone to scan all my SES codes. They gave me like 15 codes, but most of them are easy fix or due to the mods. However, these three look important.

P0332, P0327 - both knock sensors

P0412 - secondary air injection system.

The car has rebuild engine with ZO6cam, Heads, Headers with dupmed exhaust (no cats/o2 sensors) does not have EGR valve, can't locate pcv either (there is a hose from throttle body to the back of the engine, guide me please on this one)

It looks like I have to change knock sensors, but
I'd appreciate any suggestions about P0412.

I just want to make sure before I replace the sensors.

tnx

2001NBMZ28

P0412 is just a secondary air code, was SA deleted? If so just turn the code off. Don't need it anyway since you don't have cats. Stock PCV location on '98 was halfway down passenger side valve cover underneath some foam padding.

varjag

iTrader: (1)

That makes me feel better. I though it can be a problem with my air-pump.
Can knock sensors affect gas mileage?
The car gets pretty low MPG like 12 in the city (not sure about highway yet, I fill it up once, so I can not claim it), taking into account that I have 4.10 gears and my odometer reading is off I'm getting even worse than that.

2001NBMZ28

Look up the KS codes for your year at gearchatter.com too, should give you a description and diagnostics. Since both sensors are throwing a code maybe it's just a wiring issue - there's a connector behind the intake you can unhook and OHM out, gearchatter has the values. Pulling the AIR PUMP fuse under the hood on mine throws P0412 with the stock secondary air intact.

varjag

iTrader: (1)

I found some unpluged connectors on the back of the engine, not sure whether they are knock sensor wiring or not. Gonna post some pics tomorrow.