ozarkracer

I'm getting a recurring Check Eng light on my 2001 Ford Ranger 4.0L 4x4 with 0401 code (EGR low flow) according to autozone.

The engine is pinging under load (even when engine is cold), otherwise running good/starting fine. Replaced EGR valve and EGR Solenoid and still occured. I then connected a hand vacuum pump to EGR valve and it seems to work (idle craps out). I disconnected the idiotic Vapor Managment Valve (on same vaccum source as EGR) as this valve does not seem to hold a vacuum, but I am still getting check engine after driving 5-10 miles. I thought with the VMV vacuum disconnected I might see an EVAP code or check fuel cap, but still just seeing the EGR fault.

ozarkracer

I replaced the DPFE sensor and have driven about 100 miles with no check engine light. I am still getting pinging under light loads, could be the carbon problem. I was hoping getting the EGR working would stop it as it reduces the combustion chamber temp.

I am leary of that carbon procedure which flushes the crap out of the engine and could mess up 02 sensors or who know what. But its got 94K miles of highway cruising, so with the overdrive could have created a lot of carbon buildup.

TEDDYO

My '02 Ranger Edge 4.0L 4x4 has similar problems after 39K miles.
valves rattle usually when its warming up (5 to 10 minutes). The check engine light just came on. I get oil changes and service from the dealer every 4k-5k miles. The PVC was changed-out at 30K. Could this be from bad-gasoline? I always run 87-octane.

sdrummer2

I had the same code with my 96 Ranger. I replaced the egr valve and had code reset. A day later it came back on. I went down this past friday night and put 94 octane gas in it and the pinging immediately went away. The check engine light went off after driving it a little bit the next day. I know gas is expensive these days but a little better fuel may be all you need.

mikhael

Had a diagnistic on my '99 2.5. Replaced plugs, plug wires, and mass air flow sensor. It was okay for 500 mi, then began pinging again. Replaced O2 sensor w/o further diagnostic. Now it only pings uphill on a long grade. Haven't tried gas lower than middle octane grade yet but it's better than the premium I used to need.

romura

I have the same problem. I have the check engine light on, replaced wires, plugs. And still the check engine light is on. I have rough idle and loss of power. Dont know what to do now...someone help!

mikhael

Update: One week later, no pinging. Still using middle grade gas. This truck shoud run on regular. Considering reinitializing the computer with a power off.
any input?

LunaticSVT

A vacuum leak can cause pinging. If the EGR valve is not seating closed, it is the same as a vacuum leak. Look for any other possible vacuum leaks also.

mikhael

Try checking for loose vacum hoses, gas cap, oil filller cap etc. If all else fails spring for a pro diagnostic. Good luck.

mikhael

Thanks. Will try a ew EGR. Also, there's a vacum hose that looks suspect. I'll post the result.

Mikhael