'96 Z28 Throwing codes
1. P0100. MAF or VAF Circuit Failure.
2. P0300. Random Misfire.
3. P0441 EVAP Control Bad Purge Flow.
4. P0443 EVAP Purge Control Valve
5. P1642 Fc Relay (2) and Relay (3) Control Circuit
This is as the mechanic wrote it. Does Number 1 mean the MAF is bad or just the wiring? Any way to test it other than just switching it out?
Number 2 is due to fouled plugs I'm guessing due to running extremely rich which would be due to the bad MAF I'm guessing? If I'm sitting at a stop sign with the windows down you can really smell the fumes.
3 and 4 are vacuum related correct? I have one vacuum tube disconnected on the passenger side of the intake and one over by the ABS/Intake area. Would those be the correct causes? Either way I'll be figuring out where they go and hooking them back up.
Number 5 is the Fan relays correct? It did over heat a tad after messing around alittle but other than that it runs good. You can hear them turn on when I turn the ignition to the "On" position after I've been driving it.
Just want to verify what I was told so I know I'm heading in the right direction and so I'm not throwing parts at it or if there are other things that could cause it to throw these codes.
For what it's worth the car has a BBK Throttle Body, Edelbrock Shorty Headers, MSD Ignition and Moroso CAI. Could have a aftermarket MAF but I'm pretty sure it's the stock one as it came with a Granatelli MAF uninstalled. From what I've read the stock MAF's are the best though.
Last edited by oChristiano; Jun 29, 2010 at 10:58 PM.
http://www.shbox.com/1/1996_evap.jpg
take a pic of the loose line on the driver's side...
5: Check your fan relays/ wiring
1: a) Check engine sensor fuse (20A), b) check for 12V on pink wire with key on/engine off, c) if you have headers check the heat tape-wrapped part of the engine harness by the pass. side primaries to make sure they're not cooked. If they are, splice in some extra length so you can keep it out of the way and re-wrap with heat tape.
See how far you get...
I have this piece below, no idea what it is or what it does. I found the connection for it over by the ABS/Airbox. Any one know what it is? Just spent the last 2 hours at the local Chevy dealer to no avail. Need to figure out the hoses that attach to it.


Not the best pictures so bear with me.
Has the AIR injection system been deleted? (Tubes going into the headers/exhaust manifolds, plastic housing pump- on left side just aft of the waterpump, metal crossover tube going under by the oil pan & steering rack)
Edit: location is just behind the water pump, left side- not on the intake itself. You're possibly missing a piece of vacuum line. Didn't want to give the impression that you were to attach it directly to the intake nipple.
Last edited by Gojira94; Jul 1, 2010 at 04:50 PM.
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Edit: location is just behind the water pump, left side- not on the intake itself. You're possibly missing a piece of vacuum line. Didn't want to give the impression that you were to attach it directly to the intake nipple.

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http://shbox.com/1/air_pump_recall.jpg






