anyone tell me what these error codes mean?? 34,84,85

Dr. Wu 2000

New Member
Feb 16, 2004
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Eastern, Pa.
After we took some pics over at ShortThrow5.0's we pulled some error codes off my car...34, 84, 85. Done when car was not running. I think one may be for the EGR which is not hooked up, not sure what the other 2 are. :shrug: Help please.
 
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Code 34 Or 334 - EGR voltage above closed limit - Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the flange side of the EGR by mouth. If it leaks, there is carbon stuck on the pintle valve seat, replace the EGR valve ($85-$95).

If the blow by test passes, and you have replaced the sensor, then you have electrical ground problems. Check the resistance between the black/white wire on the MAP/BARO sensor and then the black/white wire on the EGR and the same wire on the TPS. It should be less than 1.5 ohm. Next check the resistance between the black/white wire and the negative battery post. It should be less than 1.5 ohm.

Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter.

Let’s put on our Inspector Gadget propeller head beanies and think about how this works:
The EGR sensor is a variable resistor with ground on one leg and Vref (5 volts) on the other. Its’ resistance ranges from 4000 to 5500 Ohms measured between Vref & ground, depending on the sensor. The center connection of the variable resistor is the slider that moves in response to the amount of vacuum applied. The slider has some minimum value of resistance greater than 100 ohms so that the computer always sees a voltage present at its’ input. If the value was 0 ohms, there would be no voltage output. Then the computer would not be able to distinguish between a properly functioning sensor and one that had a broken wire or bad connection. The EGR I have in hand reads 700 Ohms between the slider (EPV) and ground (SIG RTN) at rest with no vacuum applied. The EGR valve or sensor may cause the voltage to be above closed limits due to the manufacturing tolerances that cause the EGR sensor to rest at a higher position than it should.

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This will affect idle quality by diluting the intake air charge

Code 84 EGR Vacuum Regulator failure – Broken vacuum lines, no +12 volts, regulator coil open circuit. The EVR regulates vacuum to the EGR valve to maintain the correct amount of vacuum. The solenoid coil should measure 20-70 Ohms resistance. The regulator has a vacuum feed on the bottom which draws from the intake manifold. The other vacuum line is regulated vacuum going to the EGR valve. One side of the EVR electrical circuit is +12 volts anytime the ignition switch is in the run position. The other side of the electrical circuit is the ground path and is controlled by the computer. The computer switches the ground on and off to control the regulator solenoid.
Code 85 - CANP solenoid - The Carbon Canister solenoid is inoperative. Check vacuum lines for leaks and cracks. Check electrical wiring for loose connections, damaged wiring and insulation. Check solenoid valve operation by grounding the gray/yellow wire to the solenoid and blowing through it.
The computer provides the ground for the solenoid. The red wire to the solenoid is always energized any time the ignition switch is in the run position.

Charcoal canister plumbing - one 3/8" tube from the bottom of the upper manifold to the rubber hose. Rubber hose connects to one side of the canister solenoid valve. Other side of the solenoid valve connects to one side of the canister. The other side of the canister connects to a rubber hose that connects to a line that goes all the way back to the gas tank. There is an electrical connector coming from the passenger side injector harness near #1 injector that plugs into the canister solenoid valve. It's purpose is to vent the gas tank. The solenoid valve opens at cruse to provide some extra fuel.

It does not weigh but a pound or so and helps richen up the cruse mixture. It draws no HP & keeps the car from smelling like gasoline in a closed garage. So with all these good things and no bad ones, why not hook it up & use it?
 
Mike has EGR DELETE and SMOG DELETE. So the question is, Is there any thing to worry about? Or should he just disregard the codes. Car runs great with no issues. Just want to be on the safe side. Are there any humans in here? LOL.
 
Ther is no reason to delete either the EGR or the carbon canister on a street driven car. Removal of either or both of them will not make the car faster.

A non functional or poorly functioning EGR can cause ping condition at cruse. The computer advances the timing to compensate for the slower burning mixture. This advanced timing can cause the engine to ping if the recirculated gases are not present.

The only proper way to delete the EGR is via a custom tune chip, Tweecer or other portable programmer/tuner.
 
Im sure mike will chime in jrichker but he didnt delete it. The previous guy did. Its blocked off with a plate on the egr spacer and Im not so sure about it being blocket off with the gasket below the lower intake. There is however some sort of plug adapter going into the electircal socket that would normally be plugged in to the egr valve.
 
Car seems to be running ok at this time and these codes look like they have to do with all the stuff that is not hooked up anymore...I guess that is why it is throwing those codes.:shrug: Custom tune will be done when the $ is available so it should take care of all of them I hope. We shall see.:flag: Thanx for the info.