Just an example of how the simple and obvious things get overlooked when trying to track down the reason for a trouble code. I had various problems with the car ( poor starting / running rough / overheating etc.)
I have replaced numerous parts / sensors some of which were original.
This included:

Distributor
Coil
MAF Sensor
MAF Relays
Plugs
Coolant sensor
Oil Sending Unit
Knock sensor
O2 sensor
IAC
TPS
EGR valve
EGR Solenoid
Vacuum hoses
Thermostat
Radiator cap
Replaced various wires in wiring harness

After all this the car was running better (starts first time, does not overheat - even in traffic) but I still had a code 33 and a idle was a bit rough. Tried everything with MAF including returning new sensor for a replacement - changed relays - checked TPS etc. On diagnosis all voltages to MAF connector were good and contacts were clean.
Eventually found on an old post in the board archives someone who had similar problem and found that although MAF connector appeared okay the connectors can become a little expanded and when connected to the sensor will not make a good connection. Removed connector and crimped the connectors cleared the codes and started her up - guess what code 33 has gone !!!
Maybe I didn't need to replace the MAF and relays but at least everything is okay now.
I would like to say a special thankyou to the guys at thirdgen for their message boards - the search feature is indeed a wonderful tool!

Thanks
Andrew

88 IROC-Z 350 TPI (And no Code 33 !!!!)

 

Good job. When I first got my car I was getting codes 33 and 34, and it took a while to get rid of them. MAF cars are a pain.