Failed Emissions Test

[Mystos]

The results shown below are for a 1992 Toyota Pickup, 2wd, 4 cyl, 22RE EFI.
Idle, 881 rpm: Measured HC 180 ppm Maximum HC 120 ppm
Measured CO 2.56 % Maximum CO 1.00%
2500 rpm: Measured HC 25 ppm Maximum HC 180 ppm
Measured CO .01% Maximum CO 1.00%

Thus far I have replaced the catalytic converter, the O2 sensor before the CAT, the O2 sensor after the CAT, the Cap and Rotor, the Spark Plug wires, Spark Plugs, Throttle Position Sensor, Fuel Filter, Oil and Oil Filter, Air Filter, PCV Valve, both intake manifold gaskets (not including throttle body gasket), Tested the operation of the fuel injectors (carbuerator shop).
The resistance between pins E2 and VS on the volume air flow meter is 185 ohms (should be 200-400 ohms). Resistance increases when flap is opened.
The timing is good.
The egr valve tested good.
I have checked the evaporative canister. Applied air to the tank pipe air exited the pipe at bottom of canister. Air barely escapes out of purge pipe. Applied air to the purge pipe, air barely escapes out of tank pipe.
The above results indicate a rich fuel mixture at idle which is where my problem lies.
Does anyone have a repair solution?

Thanks for the help

G

[qsd-dan]

"The resistance between pins E2 and VS on the volume air flow meter is 185 ohms (should be 200-400 ohms). Resistance increases when flap is opened."

I'm wondering if that air flow meter is causing the problem. Best bet would be to get a used one off of ebay. There just happens to be one on there for your truck.

http://cgi.ebay.com/Toyota-Pickup-22...QQcmdZViewItem

[Nad1370]

Leaky injector. Maybe fuel leaking past the FP regulator going in the intake.

How many miles? Replaced it with a stock cat ?

[Mystos]

The VAF meter test above is out of a Chilton manual. I found another test to verify the VAF meter from a Toyota manual. I have not performed this test yet.

Initially I thought the fuel injectors were leaking as well but I had the main fuel injectors tested by a shop that rebuilds injectors and they flow tested fine. However the cold start fuel injector has not been tested.
The truck has 238000 miles on it.
The replacement cat is from a Kragen Autoparts store.

The smog tech suggested testing the fuel pressure regulator as it could be bad. Not sure how to check this yet.

Thanks for the replies.

[qsd-dan]

A quick and dirty check for the fuel pressure regulator is to pull the vacuum line off of it while the motor is runinng and make sure no fuel comes out.

[ShawnM]

Defective converter? Ive put cheap aftermarket ones on that failed by the time I drove it to the test station. Same for O2 sensors.