Hi everyone,
My 96 has thrown a CEL, and the code is PO400/0302. I have searched and I found some info on that code (I pasted it below), and I noticed a few things that I can do but I don't have any idea how to do/check each of them. The common ideas are: The EGR valve is stuck closed , and The EGR passage is clogged, how do I check these items, and then how do I fix them?

Thanks,
Zack





0302
Diagnostic Trouble code 0302 points to a problem with the Exhaust Gas Recirculation system. The malfunction is detected by the Engine Control Module when no EGR flow is detected under conditions which call for EGR. Possible causes include:
- The electrical harness or connectors (valve circuit open or shorted)
- The EGR valve is stuck closed
- Weak or dead battery
- The EGR passage is clogged
- Faulty EGR temperature sensor circuit
- A leak somewhere in the exhaust system

The EGR Volume Control Valve may be tested with an ohmmeter. Disconnect the electrical connector. Looking at the connector half which is attached to the EGRVCV with the latch at the 12 o'clock position you will see two rows of three terminals. The top row is numbered 1-3, right to left. The bottom row is numbered 4-6, right to left. Measure the resistance between these terminal pairs:
2 1
2 3
5 4
5 6
... all resistance values should be 20.9-23.1 ohms at 68 degrees F.

Reconnect the EGRVCV connector halves. Turn the ignition switch ON OFF repeatedly. Verify that the EGRVCV shaft moves smoothly forward backward according to the ignition switch position.

The Exhaust Gas Temperature Sensor may be tested with an ohmmeter. The specifications are ...
- at 32 degrees F, 0.68-1.11 Megohms
- at 122 degrees F, 0.09-0.12 Megohms
- at 212 degrees F, 0.017-0.024 Megohms

 

Bump........Any idedas?

Zack

 

Clogged EGR tube likely. Search the topic, tons of threads on this exsist.

 

I finally got arond to getting the car to a shop who ran the code. He confirmed the PO400, but he did not fix the car. He claimed that it could be one of three parts, and he was not about to start replacing parts that might not be the actual problem. So now I must find another shop to deal with this. I think the mpg's have dropped as a result of the cel.....I wish this code was more specific, and not so general.


Zack

 

The quickest way to check this problem is to read the How-To's sticky on cleaning the TB/MAF/EGR. There is one in that how to sticky about cleaning them all at once. If for some reason your EGR guide tube isn't clogged then testing and replacing parts is next.

I lit up an egr code two days ago now and after I cleared it hasn't come back. Haven't touched the egr yet so this is quite odd but I also haven't been on the road since then either but just testing with engine on in the garage.

 

i've been going thru this if for a year now. I clean my egr system thoroughly and change the egr valve already. My mech tested the solenoids and found out that the one with the balck connector in the middle does not respond. I'm trying to find the name of it, i think its the egr vaccum solenoid, its the one right next to the map/baro solenoid. YOu might want to check yours, cause my gas mileage is hurting cause of this too