Alright guys so I finally got around to checking my codes of why my check engine light is often on in my '94 F150.


Only 1 code, 327 witch is EGR Low Input Signal?

What exactly does that mean? EGR valve bad, or wiring/connecting issue?


I wanna get this fixed soon, cause 10-12mpg in a 5 speed 300, 3.08 on stock tires is pretty sad.... and plus I only cruise around 55mph on the highway, witch is the most driving I do, is on the highway.

 

DPFE or EVP circuit below minimum voltage of 0.2 volts.

I would start by testing the voltage going to those sensors

 

Where are those sensors located? (bare with me, EFI noob here).

 

EVP is located on EGR valve.

 

You can m,anually actuate the pinnel sensor and check the voltage with an accurate digital volt meter. But yeah what they said .

 

The DPFE arrived in '96 with OBD2, so he's got the older style EVP. I would start by making sure it's connected electrically. But regardless, even if the EGR is totally non-functional, it's not the cause of your bad fuel mileage. I've eliminated the EGR functional entirely, and I get fuel mileage ~50% better than what you're getting.

Have you checked your PCM to make sure you haven't got leaky capacitors? My guess is that you do, and depending on how badly they're failing, you can get all sorts of unpredictable results.

 

How do I check the PCM for leaky capacitors?

 

Open it up and you'll see three of them on the circuit board. It will be rather obvious if they're leaking. Try searching in here - you'll find lots to read on the topic and pics.