I've gotten a P0402 EGR "A" Flow Excessive code on my 95 2.3l. Most things I find online say to replace the DPFE sensor, but I don't want to throw parts at the truck. I'm up at college right now, and I didn't think to grab my Hanes manual or my factory service manual when I went home this past weekend.

What troubleshooting procedure do I take to diagnose the problem?

 

When I scan my code, I get P0402 and a pending P0401.

I am also having A/C issues under load. The A/C will default to the defrost. I'm thinking either a vacuum leak or the check valve in the vacuum reservoir.

 

yes you have a vacuum leak and probably more than one

 

I solved my vacuum leaks. Those hard likes are a pain.

I got a ELM327 cable. Currently I'm only getting the P0401 code and forscan says it's confirmed. My dpfe voltage is stuck around 4.8 or so all the time. Engine off key on, idling, and driving. Still 4.8ish volts.

 

Problem has been solved. I had an open circuit in a DPFE sensor wire. This was completely my fault. About 8 months ago I unplugged the DPFE connector while working on the truck and the connector broke. I used a zip tie to hold the connector in place. Completely forgot about it, and the zip tie eventually forced one wire to internally break. Got a connector and bit of wire from pull a part and soldered it in. Now everything is perfect.